[Tracker] [PATCH] Refactoring service-type information

[Ivan Frade <ivan frade nokia com>]

Hi all,

 Here is a patch that isolate in one module all service-type related
code. It remove some variables from Tracker struct and some functions
from tracker-utils.

 Is is also easily testeable. I have some tests already, that can be
committed after patch #521787

 Technical details and patch in:

http://bugzilla.gnome.org/show_bug.cgi?id=523200

 Please review, 

Ivan Frade