[FIX] filegals: Process file extensions properly and leave zip files completely alone

git-svn-id: file:///var/local/code.tiki.org/tikisvn/trunk@47224 b456876b-0849-0410-b77d-98878d47e9d5
[bp/r47224][FIX] filegals: Process file extensions properly and leave zip files completely alone

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/11.x@47225 b456876b-0849-0410-b77d-98878d47e9d5
[MRG] Automatic merge, branches/11.x 47213 to 47225

git-svn-id: file:///var/local/code.tiki.org/tikisvn/trunk@47226 b456876b-0849-0410-b77d-98878d47e9d5