symbols: use darray_foreach_from for nicer loop

Signed-off-by: Ran Benita <ran234@gmail.com>
doc: fix @param display for xkb_x11_setup_xkb_extension()

Signed-off-by: Ran Benita <ran234@gmail.com>
configure.ac: add -Wdocumentation

It's supported by clang and warns about bad doxygen comments.

Signed-off-by: Ran Benita <ran234@gmail.com>
test/keyseq: add test

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