Replaced all dots in roff requests with U+2302 ("house"

Replaced all dots in roff requests with U+2302 ("house"
character), and added escaping in output for all instances of dot
that are not in roff requests. This fixes the problem case where a
string beginning with a dot (for example, the string ".bashrc")
might occur at the beginning of a line in output, in which case
would mistakenly get interpreted as a roff request. Thanks to Eric
S. Raymond for pushing to fix this.