Update quick start with clone instructions for git

Signed-off-by: Jody Garnett <jody.garnett@gmail.com>
Merge branch 'master' of github.com:jive/geoserver

Conflicts:
	doc/en/developer/source/quickstart/index.rst
Merge branch 'master' of github.com:geoserver/geoserver
Merge branch 'master' of github.com:geoserver/geoserver
Merge branch 'master' of github.com:geoserver/geoserver
GEOS-5279
Improved IM filter junit tests
updating SCM location; add lin/win instructions
Minor fixes to User Guider Animator tutorial
Improved User Guide SLD Filter reference page
Copyediting GeoWebCache sections
tweaked logging null app context case, from severe to warning
logging data directory at INFO, and added setter for catalog
added constructor taking a GeoServerDataDirectory instance directly
updated constructors to take catalog interface, rather than impl
added flag to turn off extended validation, needed for system test setup
safely disposing a resource from its cache, and fixing issue not closing file stream when loading schema.xml/xsd file
handling case during cascade delete of a resource not having any layers that reference it
fixing issue not closing file stream
factored out directory removal, and made null safe