The vast majority of this is fixing up `char *` that should be `const char *`
but a handful of other fixes, like potential buffer overflows that GCC
noticed, etc, were applied as well.
This removes `-Wno-write-strings` from CMakeLists.txt, as it is no longer
necessary, as there is no longer a flood of compiler warning spam when
building.
This does not fix all compiler warnings; there are still a handful, and they
are legitimate, but they can be dealt with in a future commit.
Other modules that depends on it, can reuse includes on linking.
There some files formally not belonging any packages (lib directory), as workaround there temporary include_directories(cfile) on root of project. After migrating all modules this can be removed.
