add attributes to terms so that we can specify the bit width of MInt variables
fix Radu's comments
fix bugs in unparsing output
Merge pull request #829 from dwightguth/termattributes2

add attributes to terms so that we can specify the bit width of MInt var...
included missing lemmas
partial progress on proving list head example
z3 temp commit
progress on proving bst find in kernelc
changes to the prover to support bst find