* 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 directory used to contain both the state tracking code for the
backends, and the common utilities that could be used both by the
backends and the rest of the code. Things are now:
- src/common is utility code for the whole repo
- src/backend contains libNXT's code
- src/utils is utility code that we don't want in libNXT
This commit also changes all includes to use global paths from src/
bacause it had to touch a bunch of #include statements anyway.