Adding application/json as a mediaType to the IWC API endpoint
Fixed MySQL bugs with the data API and Profile.username

1. Fixed an issue where hibernate was not back ticking the key column
(key is a reserved word in MySQL)

2. Changed the max size of username from 256 to 255 to allow a unique
constraint on the full column in a UTF-8 schema.
DEMO: Add self link to embedded system resource on the IWC API Resource

Conflicts:
	grails-app/resources/marketplace/rest/IwcSystemResource.groovy
	src/groovy/marketplace/rest/IwcSystemRepresentation.groovy
	src/groovy/marketplace/rest/representation/out/IwcApiRepresentation.groovy