Remove IDA's cross reference comments

We're going to rename *everything*, and grep is a much more useful tool to
achieve the same.
[Reduction] #1: __abort

It begins. And this already shows that the inclusion of TH01's ZUNSOFT.COM
will double the size of all Borland C routines we slice out, because we have
to cover both large and tiny memory models...
[Reduction] #2: _strlen

Yes, I do have the .CAS files. However, even though they contain the assembly
source, they're actually C source, and we're not that far yet.
[Reduction] #3: _stricmp
[Reduction] #4: _strcpy