fix const cast warning and new/delete blocker

[lndpj]

• use uint32_t for z_crc_t instead of uLong
• fix several const char* cast warnings
• comment new/delete operator in iqm

[illwieckz]

fix several const char* cast warnings

I don't see why the return from char *strchr(const char *s, int c) should be cast to a (char *) when writing them to a char*, also strchr() doesn't return a const char* as far as I know, and casting a const char* to a char* would be wront anyway.

comment new/delete operator in iqm

Well if it builds, maybe they are unused?

use uint32_t for z_crc_t instead of uLong

I'll let maintainers decide.

To FTE:QW maintainers: beware that this contributor is just spamming Quake-derived and Math libs with hallucinated AI nonsense that doesn't even build, bringing changes no one needs, changes he cannot explain, for purposes he cannot tell.

See this comment for details:

• update CMake build DaemonEngine/Daemon#1994 (comment)

The Unvanquished project relies on the FTE:QW iqm tool in its Assets toolchain so we also have interest in this PR being handled properly: if there is one real fix to cherry-pick, it's welcome, otherwise the bin is also a nice thing to put things in.