Make leim/Makefile compute the list of .el files like lisp/Makefile

Make leim/Makefile compute the list of .el files like lisp/Makefile

* leim/Makefile.in: (TIT_GB, TIT_BIG5, CHINESE_TIT, MISC, TIT_MISC):
Make them store the .el files rather than the .elc files.
(NON_TIT_GB, NON_TIT_BIG5, CHINESE_NON_TIT, CHINESE_GB)
(CHINESE_GB, CHINESE_BIG5, JAPANESE, KOREAN, THAI, VIETNAMESE)
(LAO, INDIAN, TIBETAN, LATIN, UNICODE, SLAVIC, GREEK, RUSSIAN)
(OTHERS, CHINESE, EASTASIA, ASIA, EUROPEAN, WORLD, NON_TIT_MISC):
Remove variables listing the non-generated .el files.
(.el.elc): Add explicit load-path for quail.
(all): Depend on compile-main rule rather than $WORLD.
(changed.tit, changed.misc): Also depend on $SUBDIRS.
(leim-list.el): Don't depend on changed.tit or changed.misc.
Remove unnecessary compilation check.
(setwins, compile-targets, compile-main): New.
(clean, mostlyclean): Update for change in TIT_MISC contents.
(bootstrap-clean): Use a glob match to delete .elc, not a fixed list.