add general UI5 location prompt to script base
apply UI location to application generator and classical app template
exclude downlaoding UI5 during bower install, if custom location is chosen
exclude generating an ui5 alias in the JADS server configuration when ui5 is loaded from a custom location
add UI5 location option to Fiori template
feature(gen): add possibility to chose where OpenUI5 is loaded from (local copy installed by bower or already existing location)

If the user chooses to load the OpenUI5 API with bower, the dependencies are created in the package.json configuration and an alias is created in the JADS configuration.
If the user specifies a custom location neither the dependencies nor the alias are generated.

closes #24
refactor(JADS): Refactor to use JADS web server as a grunt plugin

Convert JADS script to a Grunt Task - published on npmjs.org as grunt-jads.
Refactor the Gruntfile.js for generated apps to use the new grunt task.