regexp search+replace for rules config

[j0hnWoods]

Comma separated list of regexp patterns and their replacements - e.g.: base64(pattern_regex):base64(replacement),base64(pattern_regex_n):base64(replacement_n)

[drk1wi]

Thanks for adding regex support. Issues:

1. Comments out ReplaceStrings in PatchHeaders (lines 292-299) - breaks Location header rewriting
2. Breaking change: literal strings like example.com become regex (. matches any char)
3. Remove commented-out code

Was disabling header patching intentional?