Icon-O-Matic: Generalize some classes

* Turns PathContainer, ShapeContainer, StyleContainer into Container.
* Makes Shape use Container for storing Tansformers instead of
reinventing the wheel yet again.
* Moves common logic from AddPathsCommand, AddStylesCommand,
AddShapesCommand, and AddTransformersCommand to AddCommand.
* Factors out common logic from two more commands similar to above.
This adds the MoveCommand and RemoveCommand classes.
* Cleans up some code style.

Change-Id: I59eca94a1c45eac608514f269f6e5f8628f93fab
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6640
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: Adrien Destugues <pulkomandy@pulkomandy.tk>

Icon-O-Matic: Add reference images

Fixes #2748

Also fixes a comment misstating a function's name and code style.

Change-Id: I609a1f1e100ded647818e70b428cedc48cf29036
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6604
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: Adrien Destugues <pulkomandy@pulkomandy.tk>

* Icon inherits from Referenceable in Icon-O-Matic mode
* new listeners receive an AreaInvalidated notification


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@18564 a95241bf-73f2-0310-859d-f6bbb57e9c96

* cleanup for consistency in FlatIconFormat.h
* used Axels proposals for vector icon attribute name
* added a BIconUtils class, currently only dealing with vector icons,
it will render a vector icon from either a BNode attribute or a flat
buffer in memory into a provided bitmap. The bitmap needs to be of
B_RGBA32 colorspace, the size of the bitmap determines the scaling
of the vector icon, width and height should currently be the same
(square bitmap)
* TODO:
- add reading of "old" BeOS icons / move icon reading from other
places (BMimeType?) into BIconUtils
- add reading icons from resources?
- suggestions?


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@18400 a95241bf-73f2-0310-859d-f6bbb57e9c96

* moved all the classes actually needed for reading a
vector icon to this place, #ifdef'd out all the editing
features (listening, referencing, converting to
PropertyObject... etc)
* TODO: put into BPrivate namespace...


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@18396 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Icon inherits from Referenceable in Icon-O-Matic mode
* new listeners receive an AreaInvalidated notification


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@18564 a95241bf-73f2-0310-859d-f6bbb57e9c96

* cleanup for consistency in FlatIconFormat.h
* used Axels proposals for vector icon attribute name
* added a BIconUtils class, currently only dealing with vector icons,
it will render a vector icon from either a BNode attribute or a flat
buffer in memory into a provided bitmap. The bitmap needs to be of
B_RGBA32 colorspace, the size of the bitmap determines the scaling
of the vector icon, width and height should currently be the same
(square bitmap)
* TODO:
- add reading of "old" BeOS icons / move icon reading from other
places (BMimeType?) into BIconUtils
- add reading icons from resources?
- suggestions?


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@18400 a95241bf-73f2-0310-859d-f6bbb57e9c96

* moved all the classes actually needed for reading a
vector icon to this place, #ifdef'd out all the editing
features (listening, referencing, converting to
PropertyObject... etc)
* TODO: put into BPrivate namespace...


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@18396 a95241bf-73f2-0310-859d-f6bbb57e9c96