created the captcha library and changed all the resolvers to use them

I got another hard crash with clicktoview resolver so I went to fix it and then decided to just go ahead and unify the captcha code. I tested clicktoview, 180upload, hugefiles, and vidplay with the unfiied captcha library. I couldn't find a megarelase link to test with. There are a few other resolvers using captcha code but they looked different than the typical code so I didn't mess with them.

Also, I tried to name the file "catcha.py" but when I did I think I must have been conflicting with some other library as I couldn't access the methods in the py file.