csharp: translating uints to '\uXX' chars

This gets us through a -T0 tranlation. What we really need though is a syntax
for char-typed values. Probably start with three basic types: unsigned, signed
and char. Using u(N), N and c(N).
added a char value type, use it to write out character vals in c#
c# test case translator now working for all test cases