system.cc, system.h, and addrspace.cc modified

I added command line argument -M to system.cc. Initialized BitMap class
called "bitmap".

Included bitmap.h in system.h

I made the physical page for the page table start at the page number
returned from the fit function within bitmap within addrspace.cc.
Adjusted system.cc to correct -M command line arg

I adjusted system.cc to correctly update fitType based on user input
from the -M command line option.
Merge pull request #1 from micahriggan/D-Branch

D branch