packman-mirrorlist: don't just overwrite but backup mirrorlist file

People can have their own settings, if they don't want to use
the GeoIP-decided servers. Don't just lose those, but back up
properly if need.
Fix configure macro to support new automake version.
Merge pull request #342 from imrehg/mirrorlist

packman-mirrorlist: don't just overwrite but backup mirrorlist file
Merge pull request #343 from tgc-dk/master

Fix for xbmc-rbp-git to support new automake version
Add package alarm/libbcm2835 for armv6h
Merge pull request #346 from cosmonaut/libbcm2835

Add package alarm/libbcm2835 for armv6h
extra/chromium to 24.0.1312.52-1
Merge branch 'master' of github.com:archlinuxarm/PKGBUILDs