Added CorDapp gradle plugin written in Kotlin and bumped the version of gradle plugins to 2.0.0 to reflect that this backwards incompatible change is a part of the on going stabilisation of the Corda gradle plugin suite.
* Added new corda and cordaRuntime configurations for cordapps to be able to explicitly depend on Corda and exclude corda dependencies from the fatjar
* Added corda integration section to docsite to describe how to integrate with Corda.
* Updated more of the documentation to reflect the new method of specifying core corda dependencies.
* Reorganised document logic to move all build system related documentation to the cordapp build systems page.
* Renamed cordapp build systems doc to match actual purpose.
* Improved the warning for building against a net.corda dependency in a cordapp
* Added a line of dialogue to show further reading for those reading about writing cordapps.
