ja.po: translation update by Koji
Japanese doc image files: updates and additions by Koji
doc files: push all changes sine master was closed and the updates from Koji
uk.po: translations for 2.1 from Yuri
Japanese docs: another update from Koji
Fix make install phase.

http://www.mail-archive.com/lyx-devel@lists.lyx.org/msg183199.html
* cs.po
Squash gcc warning.

http://www.mail-archive.com/lyx-devel@lists.lyx.org/msg183142.html
* Additional.lyx (accept changes)
* cs/splash.lyx update