Allow custom templates

[eddiemonge]

Allow the user to pass in a path to where templates they would like to use are located

[thoughtpalette]

+1

[mmahalwy]

+1

[stefanbuck]

You can use the new GlobalStorage to store the location for the next time 😉

[ajoslin103]

I love this generator, but I would like to rev the .js templates to conform to the angular styleguides: https://github.com/johnpapa/angularjs-styleguide & https://github.com/toddmotto/angularjs-styleguide

Does #546 support this? How would I use it?