Added cases for lrel to lub and typeOf.
Merge branch 'master' of https://github.com/cwi-swat/rascal.git
Added missing case for lrel in definition of Symbol
Temporary fix for all tests
Added tutor pages
Increased upperbound of nextInt to cover all cases.
Another bound issue for nextInt.
Made Cobra aware of bounded type parameters.
Fixed subtype function for lrel and list.
Merge branches 'master' and 'open-and-closed-recursion' of https://github.com/cwi-swat/rascal into open-and-closed-recursion