[cosmetic] Reformat all code

All source and build scripting code now have tabs of 2 spaces instead
of 4.
[tooling] Prepare room for integration builds

The version property shall now have '-SNAPSHOT' appended under develop-
ment and stripped when performing a release.

This will open room for integration builds that will be rapidly be tes-
ted by the example projects that are coming next.
[tooling] Add integration repositories

This adds two integration repositories. One is online, provided by the
JFrog Oss artifactory service and the other one is an offline
directory based repository located at "$buildDir/repo/integration".

This offline repo replaces the mavenLocal() one to prevent the hard
disk to get filled by several snapshot builds.

Create an install task that publishes artifacts locally in the offline
based integration repository.
[tooling] Simplify test section

Remove unnecessary cluttering, keeping only what's essential for
simple verifications in console, encouraging the check of the test
results report for a more comprehensive analysis.
[refactoring] Rename task action method

Code provides better information of what it is really doing.
[tooling] Add support for SublimeText projects
[tooling] Remove artifactId property

Any reference to the 'artifactId' property is now replaced by
'project.name' property.

bintrayUpload task now depends on local pom publication too.
[refactoring] Prepare room for Scala language switch

Plugin implementation will be switched to the Scala language. This
prepares the build to handle Scala code compilation.

Remove any groovy remaining code, as well as runtime-config files
that won't be needed anymore.

Unify plugin name, no more building different packages based on a
scala version. The plugin will handle witch Scala version to use at
runtime.

Tests that were already written using ScalaTest will be completely
rewritten also. See the next commit.
[refactoring]] Complete switch to Scala language

Plugin is now completely written in Scala 2.11. All plugin
configuration is made using the Scala's Stackable Trait Pattern,
separating each configuration concern into a different trait.

Implements the generation of proto descriptors in a new task,
'generateProtoDescriptors'.

ScalabuffExtension now allows the user to fail fast the build in case
protoc compiler is not found on path.

Remove redundant task clearProto.
[tooling] Change gradle wrapper

Make gradle-wrapper.properties point to a location that downloads
binaries, sources and javadoc, allowing IDE's to show sources in sync
with class files.
[tooling] Add gradle wrapper native scripts

Add scripts generated from the execution of the wrapper task.
[feature] Add example projects

Add single and multi project examples to show the usage of the
plugin from the perspective of a client.