SettingsActivity: Don't update connection settings if disconnected.
MPD: Fix Album Artist setting regression from 51cecb7.

Second attempt to fix this one.
MPD: Generalize parseResponse, add it to Tools.

This method caused an automated crash report, cleaned it up to use
Tools.splitResponse() which should fix the source of the crash,
then generalized it as it will be useful at a later time.
MPD: Don't suppress/log exception in the library for no reason.
use MPD's own database update time when checking for album cache
make backup of value before setting it