Fix: extensive documentation overhaul
Fix: documentation tree structure and various small usability fixes
Merge branch 'master' into doc-fixes

Conflicts:
	doc/source/02_gettingstarted/installations/index.rst
	doc/source/02_gettingstarted/installations/install-script.rst
	doc/source/02_gettingstarted/installations/install_script.rst
	doc/source/07_advanced/distributed.rst
	doc/source/07_advanced/sms-with-android.rst
	doc/source/08_configobjects/arbiter.rst
	doc/source/09_architecture/the-shinken-architecture.rst
	doc/source/10_troubleshooting/troubleshooting_shinken.rst
	doc/source/15_development/programming-rules.rst
	doc/source/98_deprecated/install_script.rst
Merge pull request #1152 from s3v/doc-fixes

Documentation overhaul