Strip quotes from color options; fixes #416

I believe the patch below fixes this issue (it does on my Windows system). I created a new subroutine that removes any single or double quotes from the given string, and then use it to modify the appropriate color options. In my test sandbox, this makes Term::ANSIColor::colored happy.

If there's a cleaner, or more succinct way of doing this, let me know. I just wanted to contribute to this great project (it's helping me learn git and improving my Perl at the same time).