major refactoring of rest access

- remove IntelliJ dependencies in rest access

Related to issue #56
major refactoring of rest access

- move code to package com.urswolfer.gerrit.client.rest

Related to issue #56
add basic example code for rest client
add copy of parts of com.google.gerrit.extensions

- disabled parts of ActionInfo
additions to com.google.gerrit.extensions

- parts which are required for plugin implementation
port rest client to com.google.gerrit.extensions api

Related to issue #56
add guice provider for GerritApi

- minor cleanups
pass auth-data to http-client-builder-extensions

- when testing a new connection, the inected auth-data (from settings) may be outdated
adopt to recent changes in Gerrit extensions-api

Related to issue #56
adopt to recent changes in Gerrit extensions-api

- minor refactorings in client code

Related to issue #56
adopt to recent changes in Gerrit extensions-api

Related to issue #56
Merge remote-tracking branch 'origin/refactor-rest-client'
bump version to v0.8.0-SNAPSHOT