COMP: Fix build error occurring when OpenSSL support is disabled

While commit r22220 added SSL support ensuring the CMake option
"Slicer_USE_PYTHONQT_WITH_OPENSSL" was disabled by default. Not all OpenSSL
related code was properly excluded, this commit ensures Slicer can be
compiled with OpenSSL support disabled.

Discussion: http://slicer-devel.65872.n3.nabble.com/Windows-build-fails-due-to-missing-QSslSocket-class-tt4029446.html

See issue #2998 and #2355

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22226 3bd1e089-480b-0410-8dfb-8563597acbee
COMP: Fix unused variable warning in qMRMLSliderWidget

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22227 3bd1e089-480b-0410-8dfb-8563597acbee
COMP: Disable OpenSSL support by default

This commit ensures the OpenSSL support is disabled by default as claimed
within the commit message associated to r22220.

Discussion: http://slicer-devel.65872.n3.nabble.com/Windows-build-fails-due-to-missing-QSslSocket-class-tt4029446.html#a4029460

Thanks Greg Sharp for reporting the issue.

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22228 3bd1e089-480b-0410-8dfb-8563597acbee
ENH: Allow temporary directory to be accessible in MRML logics.

TemporaryPath is added to vtkMRMLApplicationLogic, so that the temporary directory can be directly accessible from MRML logics.

Also add associated tests

Fixes #2416

From: Yuzheng Zhou <yuzheng.zhou@kitware.com>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22229 3bd1e089-480b-0410-8dfb-8563597acbee
ENH: Remove Qt Dependency from vtkMRMLAnnotationLogic

Following r22229, TemporaryPath can be accessible from MRML logics, the
Qt dependency code can now be removed from vtkMRMLAnnotationsLogic.

Fixes #1937

From: Yuzheng Zhou <yuzheng.zhou@kitware.com>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22230 3bd1e089-480b-0410-8dfb-8563597acbee
BUG: Prevent extension factory checkout error using git read-only url

Detect read/write git url and convert them to read-only scheme.

Fixes #2395
Fixes #2032

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22231 3bd1e089-480b-0410-8dfb-8563597acbee
BUG: 3235. Fixed return statements.

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22232 3bd1e089-480b-0410-8dfb-8563597acbee
ENH: Add support for MaximumQuality voluming rendering

High quality for CPU and GPU volume rendering mappers. Texture mapper
does not have quality control.
Issue #1752

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22233 3bd1e089-480b-0410-8dfb-8563597acbee
ENH: Add QuadBuffer stereo support

By default there is always an attempt to enable stereo capability. This is
done in ctkVTKAbstractViewPrivate::setupRendering [1].

Then, following the test done within the different implementation of
vtkRenderWindow, in case the hardware doesn't support it, the flag associated
with StereoCapability will be turned off [2][3].

Finally, the action within the threeD controller widget is enabled
or disabled based on the state of the StereoCapability flag.

[1] https://github.com/commontk/CTK/blob/4e98d9a064bfe32a4c0cb28838a093e392dc3cc3/Libs/Visualization/VTK/Widgets/ctkVTKAbstractView.cpp#L102
[2] https://github.com/Kitware/VTK/blob/0e0674a3695fdeaf01ce87dfc04e32111b7402e0/Rendering/vtkXOpenGLRenderWindow.cxx#L351-401
[3] https://github.com/Kitware/VTK/blob/0e0674a3695fdeaf01ce87dfc04e32111b7402e0/Rendering/vtkWin32OpenGLRenderWindow.cxx#L734-738

See http://www.na-mic.org/Bug/view.php?id=1578

Fixes #1578

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22234 3bd1e089-480b-0410-8dfb-8563597acbee
ENH: Custom style for slicer

Allow the slicer to use custom styles. This rests on the Qt style plugin
framework. The style plugins must be compiled with the same Qt as slicer,
in the same mode (debug, release...) and in shared library mode.
To facilitate the creation of new plugins, a cmake macro was added to
slicer cmake directory.
Every slicer style must inherits from qSlicerStyle. They are not detected
by the application otherwise.

The new styles can be set like modules. A setting page is added for them
where user can specify the directory containing his plugin. The additionnal
paths and the style key are added as settings. This means that the next
time slicer's session is opened, the application will automatically load
the custom style if it still exists.
Adding or removing paths necessit the application to be restarted. This
comes from the fact that the QStyleFactory is only updated upon its
creation which only happens when starting the application.
Changing the style however doesn't need to restart the application.
At this occasion, a Slicer dark style was added to the list of available
styles.

On the implementation side, the designer plugin export definition was
shortened and includes the "DESIGNER" term so it is different than the
style export macro.

Finaly, adding a fix to the slice controller widget label style so
it can work with the new dark style.

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22235 3bd1e089-480b-0410-8dfb-8563597acbee
ENH: Group appearance related settings together

The settings in General that are related to the slicer's look were moved
to the style setting panel. At this occasion, this panel was renamed
Appearance.
This allow a better grouping of the application customization option for
an easier user experience.

Also used the occasion to add tooltips to these options.

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22236 3bd1e089-480b-0410-8dfb-8563597acbee