Ability create IllegalRegexpRule with Pattern flags

[Ituninant]

Adding ability to create IllegalRegexpRule with Pattern flags
Example: IllegalRegexpRule with CASE_INSENSETIVE pattern flag

[dfish3r]

Created pull request:
#118

[dfish3r]

I will note that you write case insensitive regular expressions without this patch.
Use the (?i) syntax to perform a case insensitive match on part of an expression or an entire expression.

[dfish3r]

Merge request accepted.