Adds a shorthand to checkout a remote branch with the prefix "others".

Given a remote branch <b> it will execute
git checkout --track -b others/<b> origin/<b>

This is often useful when we want to checkout someone else branch but we want to clearly
distinguish it from the personal branches.
Small changes to the names
Increased number of allowed arguments
Bugfix
Merge pull request #31 from mottalrd/master

Adds a shorthand to checkout a remote branch with the prefix "others".