Documentation around glob patterns and shell expansion

[boneskull]

from mochajs/mocha#1115

Not sure if it is needed, but it may be worth noting that due to shell expansion, glob patterns should be wrapped in single quotes on unix shells.

mocha -w -r should 'test/**/*.js'

Using that would render the --recursive flag useless.

[boneskull]

This issue was moved to mochajs/mocha#3136