xkbcomp: handle XKB file include's better The 'merge_mode' situation is quite messy, and we've introduced a regression compared to original xkbcomp: when handling a composite include statement, such as replace "foo(bar)+baz(bla)|doo:dee" and merging the entire resulting *Info back into the including *Info, we actually use the merge mode that is set by the last part (here it is "augment" because of the '|'), when we should be using the one set for the whole statement (here "replace"). We also take the opportunity to clean up a bit. Signed-off-by: Ran Benita <ran234@gmail.com>