Removed old, unused stuff from the main support package.
Implemented decoding logic for SPECIAL2 instruction group, particularly for MADD, MADDU.
Instructions themselves not implemented yet in multiplier.
Refactored multiplier/divider unit.
Now uses dedicated multiplier HW, and the divider complies with C99 rules for the remainder sign.
Eventually will support optional sequential multiplier implementation.
Fixes #1
Updated the opcode tester program to account for new behavior of divider.
Amended TB support package to account for differences in divider unit.
Merge branch 'master' of https://github.com/jaruiz/ion