make force-tag gone

[Debarshi Ray]

>> I have happily used 'TAG_OPTS=-F make tag' [1] on the rare occasions
>> that I needed force-tag. I might try to use local hacks to get around
>> it if people decided to try and block 'TAG_OPTS=-F make tag'. :-)

> We will ultimately need to also disable TAG_OPTS=-F as well

... not unless we have a way to force tags keeping the various
safeguards already suggested.

Cheers,
Debarshi