change doc to doc/ in .gitignore

I think this is more inline with what's intended
Fix OptInt's valid?() function

[FixRM #7539] - The valid?() function will first normalize() the
user-supplied input before validation.  The problem is that the
normalize() function will ALWAYS convert data to integer, therefore
whatever you validate, you will always get true.  For example:
when I do "yomama".to_i, that returns 0, and of course will pass
integer validation.
[FixRM: #7535] Missing normalize() in OptPort

[FixRM: #7535] - Sometimes OptPort can return as a String instead
of Fixnum because OptPort is missing the normalize() function.
Squashed commit of the following:

commit 1beebe758c32a277e0a77f7d1011a56fda707732
Author: kernelsmith <kernelsmith@kernelsmith>
Date:   Fri Jan 11 17:55:27 2013 -0600

    fixes missing word in descript. of rails exploit

    simple omission fix in description

[Closes #1295]
Merge pull request #1296 from wchen-r7/normalize_optport

[FixRM: #7535] Missing normalize() in OptPort
Merge pull request #1278 from kernelsmith/gitignore

change doc to doc/ in .gitignore
Merge pull request #1293 from wchen-r7/optint_valid

Fix OptInt's valid?() function