ENH: Enable SSL support by default.

OpenSSL is needed:

• for python to provide the integration with github
  when using the extension wizard
• by the extension manager to display images hosted using https
• for python to install packages downloaded from https server

Note that Qt is required to be built with openssl support. The default
version of OpenSSL used on windows is "1.0.1h" and it matches the version
used by the packages available on sourceforge.net/projects/qtx64/files/qt-x64/4.8.6/msvc2008/

To build Qt from source, instruction are provided on the Slicer wiki.
See http://www.slicer.org/slicerWiki/index.php/Documentation/Nightly/Developers/Build_Instructions

Co-authored-by: Hans Johnson <hans-johnson@uiowa.edu>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@24027 3bd1e089-480b-0410-8dfb-8563597acbee