#772 New regex

[Erich]

Since we now pre-req C++ 11 we have a full-blown Regular Expression class std::regex at hand. All that's needed is an ooRexx interface.

In addition to a new regex ooRexx class, we might consider new syntax elements like

• a PARSE REGEX keyword instruction
• an "Abc" ~= "[A-Za-z]+" comparison operator
• a regex instance shorthand like "[a-z]"r (short for .regex~new("[a-z]"), which could be used with existing methods like in "Abc"~startsWith("[A-Z]"r)