Yoyo function added for frames. Quite useful for walking animations and things like that.
Formatting and cool demo updated
Merge pull request #657 from jtorrente/yoyo

Yo yo function added
Remove generated-from-json-schema java files from the repository

(They are regenerated on each recompile)
Invoke own version of jsonschema2pojo, using LibGDX Array

Use es.e-ucm:jsonschema2pojo-maven-plugin, which allows
arrayDefinition and arrayImplementation classes to be specified

Updated all accesses to the schema to refer to Arrays instead
of List or ArrayList. There is mostly a 1-to-1 translation.

Also changed the engine's schema pom, because LibGDX now has to be
available in the schema.
Add an "Indexed" annotation, showcase use from conversation.json

This annotation can be used to improve indexing and full-text search
limiting it to where it is really most useful.
Updated .gitignore to ignore generated schema classes