Fix on conditional expr

  - Pushing contextual type down parts of the conditional.
Fixing errror in Joining envs in LQ
Using GADTs for qualified names
Parsing the program with related locations

  - TODO need to transform them to absolute now
Replacing relative with absolute names and paths
Restored resolve
Compiles fully, some bug fixes

  - more to be done
More fixes
support for qualified names in extends
Restoring some TRef stuff
More fixes with TRef ..
Another fix with TRef..
Keep the aliases around at replaceAbsolute
Expanding aliases before converting to abs paths.
Minor edits
Merge pull request #71 from UCSD-PL/make_absolute_paths

Make absolute paths
Merge branch 'master' into callable-interface
Fixing callable signatures for interfaces