* clang/gcc: enable -pedantic warnings
* suppress a GCC-specific warning in stb_image
* And some clang-specific warnings
* -Wconversion (clang) -Wold-style-cast (clang+gcc)
and fix a few warnings that show up with these (and a few more with
-Wconversion on gcc, even though that's not enabled by default)
* bunch more warnings
* fixes
* remove merge error
This adds support for "natively defined" API types like callbacks that
will have to be implemented manually for each target language. Also this
splits the concept of "native method" into a set of native methods per
language.
Removes the "Synchronous error" concept that was used to make builders
work in the maybe Monad, this will have to be reinroduced with builder
callbacks.