GEMPlane::GetNsigStrips() must be public to be used in global var definition
Make Roads aware of some MC truth info if analyzing MC data
Remove last remnants of keeping track of 2D fit rank in FitCoords

This was apparently left over from some road fit debugging code that
has long since been removed (March 2008).
Update a couple of comments and formatting
Add missing cstring include (for memset)
Enable conditional compilation of Monte Carlo-related code (define MCDATA)

MCDATA requires at least Podd 1.6, while non-MCDATA should still
work with Podd 1.5. Without the MC support in Podd 1.6 via SimDecoder,
MCDATA is essentially just a non-working prototype.

Note: there is no binary compatibility between MCDATA and non-MCDATA code.
Compute reconstruction status data in MCTrack: fNHitsFound, kHitsFound
Fix binary compatibility bugs of TESTCODE