Documentation updates.
Based on Maven 3.0.5 and using more Xtext 2.4
Fixes typo in Site FAQ.
Changes puppetlint project to adhere to standard Maven layout.
Documentation improvements
Adds description to the semver project
Adds a b3 aggregation to make a Maven repository from xtext p2 sites.
Adds .gitignore for target to geppetto.m2e project.