The overloads taking a string by ref for the input text of the various
ways to display a text box would all take the input string, copy it into
a buffer for imgui and then unconditionally produce a new string once
the imgui call returned. Now we only create a new string when the return
value of the native function actually indicates that the text changed.
This makes the GC happy, and also users like me who like to make the GC
happy.
Other side effects: The assumption that the reference doesn't change if
the method returns false, which is very reasonable IMO, is now correct.
* wip2
* Implement AutoUtf8Buffer
* reformat
* Work on manual bindings
* restructure
* Name scripts properly
* Update utility functions to use ImU8String
* add overloads
* Add more overloads
* Use ImGuiWindow from gen, support AddCallback
* Use LibraryImport for custom ImGuiNative functinos
* Make manual overloads for string-returning functinos
* Make all overloads with self as its first parameter extension methods
* Fix overload resolution by removing unnecessary
* in => scoped in
* Fix compilation errors
