CC-4855: System->Preferences->Fade in/out settings: Number's format is incorrect.

-fixed
Merge branch 'devel' of dev.sourcefabric.org:airtime into devel
CC-4855: System->Preferences->Fade in/out settings: Number's format is incorrect.

-use existing function to convert seconds to time format
split upgrade.sql into more logical pieces
Merge branch 'devel' of dev.sourcefabric.org:airtime into devel
Merge branch 'devel' into 2.3.x-saas