Add GVM install and GVM candidate install

GVM is a tool for managing parallel Versions of multiple Software Development Kits on most Unix based systems. It provides a convenient command line interface for installing, switching, removing and listing Candidates.

Candidates that are currently supported are:
    Gaiden
    Groovy
    Grails
    Griffon
    Gradle
    Groovyserv
    Lazybones
    Spring Boot
    vert.x


Tested on vagrant ubuntu lucid and raring