Allow more chars to be sent unencoded and encode space as '+'.

While this produces not strictly valid query strings, it reduces the
encoding overhead significantly.

Ensure that the qrencode caches are cleared when aborting.

The caches contain pointers into memory allocated by debug_malloc()
that come from a pool that is destroied once the command returns.
We therefore have to ensure that all such pointers are cleared in all
cases before returning from the command or we will run into errors
when executing the next commands.

Use a shorter URL and query to maximize payload space.

Allow aborting the command while QR codes are generated.

Add qrwebpost to generate URLs for easier data collection.

Using the qrwebpost debugger command one can initialize an id for
subsequent QR codes. All QR codes generated following such an
invokation produce URL QR codes that link to an online service that
concatenates all data with the same id and later allows it to be
displayed/downloaded in one piece. This makes collecting larger amounts
of data more convenient. Note though that the URL encoding does waste
space and therefore reduces data density, causing more QR codes to be
generated for the same amount of input data.

Add module code that wraps qrencode and does the printing.

* Generates QR codes using the qrencode library functions and prints them
using terminal escape sequences and the special "block" characters.
* Supplies a static QR buffer that can be used to accumulate output for
later conversion into QR codes.
* Adds qrencode debugger command that allows to generate QR codes for
arbitrary strings.
* Adds qrappend, qrflush and qrclear to manipulate the QR buffer.
qrappend can be the target of a pipe to accumulate output from other
commands. qrflush causes the QR buffer to be encoded and cleared and
qrclear only clears the QR buffer.
* Adds qrconfig that allows changing the QR code version, determining
what size QR codes are to be used.

Allow more chars to be sent unencoded and encode space as '+'.

While this produces not strictly valid query strings, it reduces the
encoding overhead significantly.

Ensure that the qrencode caches are cleared when aborting.

The caches contain pointers into memory allocated by debug_malloc()
that come from a pool that is destroied once the command returns.
We therefore have to ensure that all such pointers are cleared in all
cases before returning from the command or we will run into errors
when executing the next commands.

Use a shorter URL and query to maximize payload space.

Allow aborting the command while QR codes are generated.

Add qrwebpost to generate URLs for easier data collection.

Using the qrwebpost debugger command one can initialize an id for
subsequent QR codes. All QR codes generated following such an
invokation produce URL QR codes that link to an online service that
concatenates all data with the same id and later allows it to be
displayed/downloaded in one piece. This makes collecting larger amounts
of data more convenient. Note though that the URL encoding does waste
space and therefore reduces data density, causing more QR codes to be
generated for the same amount of input data.

Add module code that wraps qrencode and does the printing.

* Generates QR codes using the qrencode library functions and prints them
using terminal escape sequences and the special "block" characters.
* Supplies a static QR buffer that can be used to accumulate output for
later conversion into QR codes.
* Adds qrencode debugger command that allows to generate QR codes for
arbitrary strings.
* Adds qrappend, qrflush and qrclear to manipulate the QR buffer.
qrappend can be the target of a pipe to accumulate output from other
commands. qrflush causes the QR buffer to be encoded and cleared and
qrclear only clears the QR buffer.
* Adds qrconfig that allows changing the QR code version, determining
what size QR codes are to be used.