STYLE: Display Slicer revision at configuring time. Fixes #2020

See http://www.na-mic.org/Bug/view.php?id=2020

git-svn-id: http://svn.slicer.org/Slicer4/trunk@21895 3bd1e089-480b-0410-8dfb-8563597acbee
STYLE: Change configure time message to use main application name.

If SlicerApp_APPLICATION_NAME is set to "Foo", message like the following
will be displayed instead:

-- Configuring Foo version [4.2.0-2013-04-16]
-- Configuring Foo revision [21891]
-- Configuring Foo for [linux-amd64]

git-svn-id: http://svn.slicer.org/Slicer4/trunk@21896 3bd1e089-480b-0410-8dfb-8563597acbee