[Reduction] #169-170: fgetn and fread

... yeah, just because ZUN decided to use the C file functions to read
reiiden.cfg for a change. OK, can we *finally* include master.lib's bgm.inc
now?
[Reduction] #171: _bgm_bell_org

[Binary change] db 0 → nop before the function in every affected executable.
[Reduction] #172: BGM-related internal data

Initializing the BSS data to 0 instead of the ? in the original source file
avoids size changes in the MZ header.

[Binary change] Order of 5 relocations in TH04's and TH05's MAIN.EXE.