ProjectListProcessor: Don't use GerritURL

ProjectsListProcessor does not need GerritURL as it can generate it from
 the current Gerrit instance. We also don't need to add parameters when
 listing projects.

Change-Id: I5132298fee1fb6d8dab214c69f84fd8a3a18601b
More dimension extraction and cleanup

Change-Id: Id9974a0b0da88f2231ce796a8a8b4cdbbdec1a5a
SyncProcessor refactoring

Change-Id: Id3547528e8fcf56d7eb0ca8ea549ed30584142ec
Store change number in SelectedChange

Store change number along with changeID in SelectedChange as fetching
 change details uses the change number.

Change-Id: I4e689de6661f55108199c0e67343c0e40e1976a0