Add function which parses MS network capability IE value for bits
indicating support for particular version of GEA.
Change-Id: I785cef37dd272a2fab9b172f6e1392f865174e9a
Relates: OS#1582
The definitions in this header file (and associated strings in the
c file) are generic about the GPRS Layer3 signalling protocols, and
thus should be part of the library.