Fix Windows QT5 Paths

.. no longer need to append 'GoldenCheetah' to the location
   since on QT 5 the executable name is used, which is GoldenCheetah

.. by sticking with this we can rename the binary to use a different
   location, which may be useful for testing
Windows Libusb / UsbXpress should be optional

.. ANT.cpp now happily compiles with no USB support
   present on Windows -- which means ANT will obviously
   no longer work, but that may be intended.
Fix SEGV on QuarqRideFile Windows QT5

.. delete the process later in the event loop.
Fix redefinition of signal in RideNavigator

.. introduced when refactoring AnalysisSidebar
Disable Drag/Drop Ride on Windows QT 5

.. it crashes !

.. we need to wait for QT 5.3.1 when this bug is
   fixed: https://bugreports.qt-project.org/browse/QTBUG-37813
Clear Web caches between restarts

.. stops lots of LEAK warnings that are related to the
   javascript garbage collector (QT5).
Antialias is now on BY DEFAULT
Default linewidth smaller

.. was 2.0px now 0.5

.. no longer looks like it was drawn with a crayon by default !
Use QT 5 Video Playback

.. If you build with QT 5 then we now use the QT video widgets
   instead of VLC for Windows and Linux

.. We still use QuickTime for Mac OS X

NOTE: On linux Gstreamer is used and therefore all the right
      codecs and backends need to be setup for this to work.
      On windows its more complicated as it depends how Qt
      was compiled, see:

         http://qt-project.org/wiki/Qt_Multimedia_Backends
Remove qDebug from NullController

.. only used in testing but still irritating !
For Pete and his Son

.. smaller cranks for the next Jack Bobridge !
Fix Library/GoldenCheetah bug

.. its complicated .. basically, if a local directory exists it will
   *always* be used for application settings.

.. when you run GC for the first time with a local Library/GoldenCheetah
   then the HOMEDIR_GC will not be set as there is no config in there

.. the code checks this setting for blanks (but that fails because the
   value actually returned is "0") and so the local library is set to the
   value returned "0"

.. but the local library doesn't exist so it falls back to opening from
   the default location but using config from Library/GoldenCheetah !

.. the next time you launch all this gets resolved and you use
   Library/GoldenCheetah with the settings you set the last time.

Fixes #936
Fixup a few string literal from QVariant issues

.. bug related to appsettings and "0" string occurred in a
   few places -- this fixes and post fixes that.
Fix up Library/GoldenCheetah and GC_HOMEDIR

.. fix the prior fix. ugh.
Fix SEGV and more when athlete home changed

.. segv removed caused by signalling configChanged when context has been
   deleted due to all the mainwindows being closed

.. check for path being reset to blank as well as being set to a different
   place.
Fix 2secs ride plot fencepost errors

.. multiple off-by-one errors working together to truncate the
   ride plot by 2 seconds.

Fixes #935
Merge remote-tracking branch 'upstream/master'