Fixed regular expression validating nicks to include capital letters.

[stylesm]

Fixing https://plus.google.com/u/0/112878679044121259004/posts/HPC9VGJZ5bT?cfem=1

[mattford]

Allows capitals in nicknames, this is because I didn't make the regex case insensitive - there is a way to do this using Java's String.matches method but this way is just as easy