Basic integration of Bazaar VCS

This patch adds basic integration of Bazaar VCS.

It provides implementation of KDevelop::IDistributedVersionControl interface as a plugin.
It works by forwarding (user) requests to bzr executable (which must be in PATH) and parsing (text output) result from spawned bzr process.

REVIEW: 118481

From def47e055f9a56af404f51b80301665c39106036 Mon Sep 17 00:00:00 2001
From: Maciej Poleski <to.java.project.d8fj39saldkj28@gmail.com>
Date: Tue, 10 Jun 2014 21:11:31 +0200
Subject: [PATCH 1/1] Basic support for Bazaar VCS
SVN_SILENT made messages (.desktop file)
Make it possible to show multiple toolviews again.

This was broken by the recent refactoring. The first call to
showWidget had the proper value for forceGrouping, but note that
this function triggers a recursion as it sets the checked property
of the action.

Instead, we now use the raise property for that, but set it
in buttonPressed, outside of showWidget.
Cleanup and reduce code.