Regex search: allow for literal search of special regex chars

Regex search: allow for literal search of special regex chars

Parentheses "(",")" and curly braces "{","}"are escaped now
and not interpreted as regex characters.
This allows for searching broadcasts with -s "Das.*Leben (2)"
which matches the title "Das gute Leben (2)".
Previously "Das gute Leben (2)" led to empty search result
as the paraenthes are used in regex to capture groups.