Log Message:
Update skk to 14.0.91.
Based on PR#43649 by Ryo ONODERA.

Back from snapshot release, so version scheme also back from timestamp.
This release is still alpha release, but, yes, better than snapshot,
and need to support of emacs23.

While here,
* set LICENSE=gnu-gpl-v2
* simplify PLIST.
* fixes paths for tutorial file in setup file
* change to use MAKE_FLAGS instead of MAKEFLAGS, it affect subsequent
  make, e.g. failed to build of emacs for resolving dependency.