stargate focus icons

git-svn-id: https://freeorion.svn.sourceforge.net/svnroot/freeorion/trunk@5681 dbd5520b-6a0a-0410-a553-f54834df5b05
corrected capitalization of gysache icon filename entry to lower case (necessary to work at least for Linux)

git-svn-id: https://freeorion.svn.sourceforge.net/svnroot/freeorion/trunk@5682 dbd5520b-6a0a-0410-a553-f54834df5b05
Merge remote-tracking branch 'svn-mirror/master'