Fixed test case by using CppSharp.AST.Extensions.
Fixed native symbol naming.

We now properly name the internal ctor declarations by constructor type.
We also now keep an index for each function that is used to unique their native name.
Fixed CheckDuplicatedNamesPass to work with functions.
Fixed trailing whitespace.
Added support for default values of parameters.
Signed-off-by: Dimitar Dobrev <dpldobrev@yahoo.com>