Fix issue 121 replacing songbird protocol by ngale

This replace the current songbird: protocol by ngale: so there is no conflicts between the two apps.
second part of fixing #121
test commit to make sure the mac buildbot is still working (and the others too, for that matter @GeekShadow - we need to coordinate build times sometime)
end the test commit
add addons url in the branding
Replace Add-ons URL by add_ons.url
remove songbird wiki links from README
Updated splash screen
Replace every ... by … in en-US
Reverse inner double-quotes by single-quotes
Add section for config deps in README and add libnotify dep info
Update en-US locale with past changes from L10n work
Use correct cflags
remove unused vars
add a sed line to modify the launcher for now to point us at gstreamer-1.0 and also a line to force gstreamer-1.0 on this branch