Allow induction on terms instead of simply names
Added tactic for case analysis.
Also, induction now work on expressions instead of simply names.
Final cleanup/check of case tactic implementation
Merge branch 'master' of https://github.com/idris-lang/Idris-dev into feature/casetactic

Conflicts:
	CHANGELOG
Merge pull request #1302 from ahmadsalim/feature/casetactic

Added tactic for case analysis.