extend the AOD content for EXO Long-Lived needs

This is a pull request to test the changes discussed during the "Scouting Parking & Hotline" workshop.
Regarding the possibility to extend the AOD content to include dE/dx information associated to highPt Tracks as well as the Muon segments (DT and CSC) and hits (RPC).
Instead of creating at least 3 new skims for the EXO Long-Lived searches.

This PR is meant to allow @StoyanStoynev and @slava77 to see what are the proposed changes and to study their impact on the reconstruction and disk space
Automatically ported from CMSSW_7_3_X #6532
- we should avoid public data members.
- Please list on a single line and add comments, preferably starting with ``` /// ``` or ```//! ``` to be parsed by doxygen.
- the default constructor has to explicitly initialize all basic type data members
- can we have Local2DPoint?
- detId should probably be DetId
- what's the unit of charge (somewhat going to the point of adding comments), why is it a float? If it's some ADC counts, then this could probably be made into an (unsigned) integer, and return a scaled value