Add support for the `nodejs` plugin

Adds support for the [NodeJS plugin](https://wiki.jenkins-ci.org/display/JENKINS/NodeJS+Plugin).
Add support for the `golang` plugin

Add support for the [Golang Plugin](https://wiki.jenkins-ci.org/display/JENKINS/Go+Plugin).
updated Gradle JPI plugin to 0.7.1
cleanup
Merge branch 'nodejs'
added missing info
added info about seed job parameters
cleanup
Merge branch 'golang'

Conflicts:
	docs/Home.md
	docs/Job-reference.md
	job-dsl-core/src/main/groovy/javaposse/jobdsl/dsl/helpers/wrapper/WrapperContext.groovy
	job-dsl-core/src/test/groovy/javaposse/jobdsl/dsl/helpers/wrapper/WrapperContextSpec.groovy
Add support for the `http_request` plugin

Add support for the [HTTP Request Plugin](https://wiki.jenkins-ci.org/display/JENKINS/HTTP+Request+Plugin).