[PATCH 1 of 3] lfs: always exclude '.hg*' text files

[Jun Wu]

Excerpts from Yuya Nishihara's message of 2018-01-23 21:07:47 +0900:
> My original question was whether it makes sense to forcibly exclude .hg*
> files (e.g. .hgtags) from lfs. That seems totally fine, but fewer "if"s
> might be better on the other hand.

I see. In theory .hgtags do not need to be treated specially - it should
work even if it's LFS. I also like less "if"s and more flexible for power
users. Given the fact that the filter language is expressive enough to
exclude .hgtags. I personally think documentation would be enough, i.e.
say something like "you might want to exclude .hgtags in lfs.track".