ast-build: fix leak in error path

Signed-off-by: Ran Benita <ran234@gmail.com>
keycodes: fix keymap compilation with no aliases and malloc(0)==NULL

If the keymap doesn't have any key-aliases (which is certainly
possible), the calloc(num_key_aliases, ...) is allowed to return NULL
according to the C standard, but this is not an error.

Signed-off-by: Ran Benita <ran234@gmail.com>
build: use symbol versioning

Symbol versions provide a means by which ELF utilities can determine
whether a program is incompatible with a too-old library version so
that package management tools can autodetect version-based
dependencies and suggest upgrade paths.

[ran: swap xkbcommon.map and xkbcommon-x11.map]

Signed-off-by: Jan Engelhardt <jengelh@inai.de>
Signed-off-by: Ran Benita <ran234@gmail.com>
Remove compatibility symbols

Remove the deprecated symbols that were used for ABI compatibility
during the transition period to the first stable version, 0.2.0.

The old *names* can still be used, programs which use the old names will
continue to work, as long as they were compiled against a stable
version (as they have been #defined to the new names from the start; see
xkbcommon/xkbcommon-compat.h). Namely, this will break binaries which:

1. Were compiled against a pre-stable version of libxkbcommon, and
2. Are linked against the next version of libxkbcommon, and
3. Expect to work.

This scenario is very unlikely, and will break in many other ways
anyway. Also, retaining support for these means including them in the
new symbol version file, which I would like to avoid.

Signed-off-by: Ran Benita <ran234@gmail.com>