Fix invalid LLVM generated for constant array. Issue #13
Improvements to subtype constraint checking. Fix issue #14
Tweak to loop termination in sem_check_subtype
Tweak to iteration in sem_check_subtype
Improve checking of attribute references
Fix bug when waiting on sub-element of a signal
Refactor group_nets a bit
Parsing for aggregate target of signal assignment
More helpful error message for aggregate targets of signal assignment
Merge branch 'master' into fst