Mark reactor default countdown times as const
Make weapon.c more like D2X
Convert HAS_*_INDEX to use helper macro
Move new_baldguy_pcx inline
Add unused weapon_info_read_n parameter file_version to match D2X
Move PCX filenames onto stack

PATH_MAX*2 is cheap, and this improves the quality of the error message
on failure paths.
Fix recvfrom prototype mismatches

Win32 uses int* instead of unsigned int*.  Fortunately, socklen_t is
defined to the correct type in both cases, so use socklen_t and let the
compiler sort it out.
Mark titles.c functions static