Added the new C++/CLI free parser.

I benchmarked it and it's about the same speed in Release mode (maybe a bit faster) but 3x slower in VS Debug mode due to all the STL usage.
Move all the code in the old parser to the CppSharp::Parser namespace.
Added a bindings generator for the new parser.
Updated the Clix string wrapping code to the latest version with some bug fixes for empty/null strings.
Updated the build for the new parser.
Revert "Move all the code in the old parser to the CppSharp::Parser namespace."

This reverts commit 6297ec532e5a38b11fc7d701388410cdf8a4ece8.
Added C# and C++/CLI bindings to the new parser APIs.
Added new ICppMarshal interface used to marshal objects.
STL containers wrappers now implement ICppMarshal (stubs).
Fixed the resolution of overloads for conversion operators.

Signed-off-by: Dimitar Dobrev <dpldobrev@yahoo.com>
Added two hacks: one for operators in general, one for a parser issue.
1. Visit the class as a declaration context when checking operator overloads - otherwise operators in nested types are not checked; this is, however, not the proper solution because all visiting of classes should be refactored so that this and any other methods are always called as necessary;
2. A single conversion operator in Qt misleads the parser into resolving a function pointer while it is (most probably) not; this caused a subsequent crash.

Signed-off-by: Dimitar Dobrev <dpldobrev@yahoo.com>
Updated the news about the conversion operators.

Signed-off-by: Dimitar Dobrev <dpldobrev@yahoo.com>
Added a test about the type def - to a function pointer -  incorrectly resolved to void*.

Signed-off-by: Dimitar Dobrev <dpldobrev@yahoo.com>
Added a test about operators in nested classes.

Signed-off-by: Dimitar Dobrev <dpldobrev@yahoo.com>
Fixed the issue about member pointers not pointing to a function. Turns out this is some "pointer to a data member" (?!) that is of little use so just ignore it.

Signed-off-by: Dimitar Dobrev <dpldobrev@yahoo.com>