feature/charset

[mplucinski]

This is rebased and improved version of pull request #3.

Changes:

• rebased onto current master
• added commit 0fe5125 - which allows test-charset to verify C++ scanner too
• added commit 2385656 - which fixes issues detected by 0fe5125 (allows to use charsets in C++ scanners)

[westes]

Thanks.

Although you can also just push to the tip of your branch and github will update the pr accordingly.