Fixed command line utility

 * Enabled support for output folder option on command line
 * Fixed issue where folder needed to exist already
 * Added support for singlePage option being set in the json config file
 * Add mkdirp dependency
 * Fixed a few places where promises where not coming back, so errors never got propagated
 * Fixed template files location issues
 * Fixed bug when an item didn't have a subMenu, nav would error out

Way too big of a checkin this time around. These should be separate. But the script is still early in its life, so I figure fixing the breaking issues is more important. :)