Convert the C# backend to the new blocks system.
Renamed C++/CLI runtime helpers to CppSharp.h.
Output the runtime helper in sources instead of headers.
Use fully qualified names in C# to minimize the chance of conflicts.
When checking for ignored declarations, return early if the declaration is already ignored.
Clean up the console driver by emitting file parsing diagnostics in the main driver.
Add the enumeration item expression as a string to the AST.
Re-work handling of enum constants fixing signedness and formatting issues.
Clean up driver.
Reference classes now implement the ICppInstance interface.

This will be used to add support for overrides of Equals and GetHashCode.
Added support for IsOverride in the generators.