C++port

* `or` is changed to `alt` due to it being a restricted keyword

* The modifiers are somewhat different, due to the differences in flags that it supports.

* There is an external dependency on boost_regex that will go away once c++ has a working regex implementation in gcc and libstdc++.

I also have this with and example script and makefile @ https://github.com/whackashoe/CppVerbalExpressions, if you like I can add them to branch.