Add nodemon to gulp flow and construct full default task

Closes #29.

All files should rebuild properly off the default `gulp` task, and Node'll restart if any of its files are updated.

Also added a `build` task to just assemble the clientside app and LESS.
Just built one of these in Grunt for the first time... what does the caret mean? Didn't see it [here](https://www.npmjs.org/doc/json.html).