Fix errors with variable names with hyphen in git setup scripts

Specifically, several of the git setup scripts defined a function named "egrep-q". This almost always works, but I happened to have an install of git on windows/cygwin that gave the error:

`egrep-q': not a valid identifier

I always thought hyphens were allowed in script identifiers (and usually they are), but apparently sometimes they are not. (See for example https://stackoverflow.com/questions/2821043/allowed-characters-in-linux-environment-variable-names). This provides an easy fix by replacing egrep-q with egrep_q.