Revert the Codec Kit.

All of Barrett's individual reverts have been squashed into this
one commit, save a few actual bugfixes.

Change-Id: Ib0a7d0a841d3ac40b1fca7372c58b7f9229bd1f0

PluginManager/AddOnManager: Add streamers support code

AddOnManager: Initial support for streamer addons

media_kit: Add encoding support facilities

libmedia: Put AddOnManager into BPrivate::media namespace.

The AddOnManager was in the global namespace, clashing with application
classes with the same name.

The input_server has an AddOnManager of its own. When the
shortcut_catcher filter was loaded by said AddOnManager, it in turn
loaded libgame.so, which in turn loaded libmedia.so, where an
AddOnManager was created for the global AddOnManager instance in
libmedia.so. Unfortunately the wrong AddOnManager, the one from the
input_server, was created. This lead to two AddOnManagers being active
in the input_server which very well could be responsible for #11049
and #11280.

This was a regression since the move of the AddOnManager from the
media_server to libmedia.so in hrev47086. This also fits with the two
tickets.

I actually noticed the problem when debugging the shutdown process of
the input_server, where the destruction of the wrong AddOnManager
caused a deadlock with itself.

Register media add-ons on BMediaFormat::GetFormatFor().

* Fixes #11018.
* In this case the FormatManager format list is accessed without going
throught the AddOnManager, so we must tell the AddOnManager to register
the add-ons (as this is what populates the FormatManager format list).
* Remove now unneeded workaround in mp3_decoder_test.

Urpdate AddOnManager and FormatManager for Media Kit

* These classes were moved from Media Server, making the use of ports
and messages to communicate with the app irrelevant.
* Split in a separate commit to help git keep track of moved files.

Fixes #4893.

Move media plug-in support to application side.

The media server tried to use node monitoring to dynamically add and
remove plug-ins, but it isn't that useful:
* When a plug-in is added, applications would have to query the media
server to get an up to date list of available formats. For example
MediaConvert populates its format menus on startup.
* When removing a plugin, if an app already had it loaded, there is not
much that can be done to keep it working.
* The list of plugins was not sorted by directories (user vs system
add-ons), so the directories were re-scanned to make sure user add-ons
were returned first, rendering the node monitoring less interesting.

Now, the format handling is done by each application. The node
monitoring is removed, instead the apps will scan the plugin directory
when first using the media kit classes. Restarting the application is
needed to update the media formats list.

libmedia: Put AddOnManager into BPrivate::media namespace.

The AddOnManager was in the global namespace, clashing with application
classes with the same name.

The input_server has an AddOnManager of its own. When the
shortcut_catcher filter was loaded by said AddOnManager, it in turn
loaded libgame.so, which in turn loaded libmedia.so, where an
AddOnManager was created for the global AddOnManager instance in
libmedia.so. Unfortunately the wrong AddOnManager, the one from the
input_server, was created. This lead to two AddOnManagers being active
in the input_server which very well could be responsible for #11049
and #11280.

This was a regression since the move of the AddOnManager from the
media_server to libmedia.so in hrev47086. This also fits with the two
tickets.

I actually noticed the problem when debugging the shutdown process of
the input_server, where the destruction of the wrong AddOnManager
caused a deadlock with itself.

Register media add-ons on BMediaFormat::GetFormatFor().

* Fixes #11018.
* In this case the FormatManager format list is accessed without going
throught the AddOnManager, so we must tell the AddOnManager to register
the add-ons (as this is what populates the FormatManager format list).
* Remove now unneeded workaround in mp3_decoder_test.

Urpdate AddOnManager and FormatManager for Media Kit

* These classes were moved from Media Server, making the use of ports
and messages to communicate with the app irrelevant.
* Split in a separate commit to help git keep track of moved files.

Fixes #4893.

Move media plug-in support to application side.

The media server tried to use node monitoring to dynamically add and
remove plug-ins, but it isn't that useful:
* When a plug-in is added, applications would have to query the media
server to get an up to date list of available formats. For example
MediaConvert populates its format menus on startup.
* When removing a plugin, if an app already had it loaded, there is not
much that can be done to keep it working.
* The list of plugins was not sorted by directories (user vs system
add-ons), so the directories were re-scanned to make sure user add-ons
were returned first, rendering the node monitoring less interesting.

Now, the format handling is done by each application. The node
monitoring is removed, instead the apps will scan the plugin directory
when first using the media kit classes. Restarting the application is
needed to update the media formats list.