Update pt_BRO translation by Tucalipe
closes ticket #4164
Update it.po by Alpha93
closes ticket #4174
Update el.po by Nikos
closes ticket #3703
Update hu.po by MeszarosTomi

Note to updater, keep line endings the same as the original,
and also name the po file correctly as well.

closes ticket #4250
Merge branch 'bugfixes' into 3.1
make -Cpo update-po
Bump version for 3.1.2 (RC)
    [NOTE: no tags for this one!]

    (cherry picked from commit 816556d8e48b7bf74d479e189ae3f30a757e5c58)
    (cherry picked from commit f6e8dad9c442d2f456f9ddab00d83ec3780181ef)

    Conflicts:
    	win32/warzone2100_portable.rc