Remove regular expression support.

[katmagic]

Supporting regular expressions breeds confusion and uses precious cycles. Three options should be implemented: -b to match at the beginning of the .onion, -m to match anywhere, and -e to match at the end. This should simplify things a bit.

[antel]

regex should be added as an option -regex but NOT removed

[torzeljko]

I agree with antel. I find regular expression support very handy, especially with doing things like ^blahblah[2-7] to constrain the character after the word I'm looking for to a number to separate it from the gobbledygook that follows. However, that being said, a simpler non-regex option would be a good idea for those with simple needs and a slower computer. :P