got rid of SiStrip in almost all places

- interface/Phase2TrackerRawToDigiUnpacker.h was a left-over
- changed the namespace sistrip to Phase2Tracker
- cleaned all useless includes to *SiStrip*

The only place where sistrip still enters is via the cabling that sits in SiStripObjects.
removed CVS vestiges
Protected the debug string operations
implemented various comments from Slava

- CVS vestiges
- header protections
- remove forward declaration file
- make accessors const
- make setters void
- clean old comments
- improve naming conventions (no underscores)
splitted Phase2TrackerFEDBuffer.h as requested + cleaning