Fix #40 and #41
Merge branch 'working'
Merge branch 'working'
Added defs
More comments
Merge branch 'working'
Merge branch 'working'
add if-then-else
resolving merges
removed comments
Fix #10
Merge branch 'working'
Merge remote-tracking branch 'upstream/master'

Conflicts:
	grace/lang/typecheck.rkt
Merge branch 'master' into working
Fix #29
Add new tests for classes