dconf writes on login

Many (45) writes are occuring to dconf on login to a unity guest session. ideally, this number should be zero. attached is the 'dconf blame'.

The writes are broken down as follows:

23 writes: Unity writing the 'average-bg-color' for each frame of the fade
10 writes: gsettings-data-convert erroneously migrating vendor overrides
8 writes: indicator datetime writing various defaults
3 writes: unity favourites migration
1 write: gnome-settings-daemon writing to the background picture-uri for some odd reason

The 23 writes from Unity are being reduced to 1 here: https://code.launchpad.net/~gordallott/unity/bghash-only-emit-on-change/+merge/94161 but they should be reduced to zero.

The 10 write sfrom gsettings-data-convert is a sort of double bug. First bug is that it appears that gsettings-data-convert is being run twice. Second bug is that on each run, it migrates the vendor overrides from GConf as if they were user settings. This bug is upstream here: https://bugzilla.gnome.org/show_bug.cgi?id=671581

We should also uncover the reason for the two runs.