Merge pull request #150 from TehMillhouse/new_call

Firm graph construction for function calls, array accesses and allocations
Add position to AST
Add positions to errors and tests
Merge pull request #136 from soc/topic/opt

Positions in AST, errors and tests
Update SBT to 0.13.7
Merge pull request #151 from soc/topic/sbt-0.13.7

Update SBT to 0.13.7
Implement remaining TODOs