Feature request: advanced regex patterns

[John Stebbins]

I love the program. It is very useful to me... after I comment out the code that strips out characters that are important for creating regex patterns. It would be nice if there were a checkbox that switched between your simple user friendly pattern syntax to the more powerful full regex syntax. When the checkbox is checked, it would just bypass those few lines of code in pyrenamer_filefuncs.py that replaces [, ], (, ), ?, and '.'.

This is usefull for doing mass renamings when many files have similar names and the mapping to new names has subtle dependencies. For example substring:
 "S1" -> "s01" pattern "S([0-9])" replacement "s0{1}"
vs.
"S10" -> "s10" pattern "S([0-9][0-9]) replacement "s{1}"