Interim commit.  Updates and fixes.
	modified:   AstroImage.py
	modified:   AutoCuts.py
	modified:   BaseImage.py
	modified:   Control.py
	modified:   FitsImage.py
	modified:   Mixins.py
	modified:   Settings.py
	modified:   gtkw/FitsImageGtk.py
	modified:   gtkw/GingaGtk.py
	modified:   gtkw/example1.py
	modified:   gtkw/plugins/Info.py
	modified:   gtkw/plugins/Pan.py
	modified:   gtkw/plugins/Pick.py
	modified:   gtkw/plugins/Preferences.py
	modified:   gtkw/plugins/Thumbs.py
	modified:   gtkw/plugins/Zoom.py
	modified:   qtw/plugins/Info.py
	modified:   qtw/plugins/Zoom.py
	new file:   util/make_release.py
	new file:   util/mosaic.py
	modified:   version.py

- Added new controls for Zoom in Preferences
  - new zoom alorithm added.  Choices are "step" (old) and "rate" (new)
  - rate algorithm allows control over stretching pixels in X or Y, and
      changing the rate of magnification per zoom step

- Added new controls for Pan in Preferences
  - shows precise pan position and allows to set manually
  - control for debugging pixel mapping by "Mark Center" toggle: shows
      a small red cross in center of screen

- Reorganization of Preferences pane to put most important controls first

- Bug fixes:
  - fixed a bug in pan setting (off by one pixel)

- Enhancements:
  - Implemented new class in Settings in order to share settings between
      FitsImage instances (reduces need for copying attributes)
    - most option control variables migrated (self.t_<var>)
    - to eventually be merged with Preferences
    - allows better code organization with different FitsImage instances
        and GUI controls (more MVC-like)
    - should eventually be able to deprecate many FitsImage callbacks

  - BaseImage now supports callbacks, will be able to notify views if
      data changes in the background

  - Added a rough image mosaicing function based on WCS mappings.  See
      util/mosaic.py

- Version bump to 1.3 to reflect lots of changes since 1.2
Bring Qt version up to latest changes in Gtk version

	modified:   gtkw/plugins/Pan.py
	modified:   gtkw/plugins/Pick.py
	modified:   gtkw/plugins/Preferences.py
	modified:   qtw/FitsImageQt.py
	modified:   qtw/GingaQt.py
	modified:   qtw/plugins/Info.py
	modified:   qtw/plugins/Pan.py
	modified:   qtw/plugins/Pick.py
	modified:   qtw/plugins/Preferences.py
	modified:   qtw/plugins/Thumbs.py
	modified:   qtw/plugins/Zoom.py
Updates to the zoom/stretch code and settings

	modified:   AstroImage.py
	modified:   BaseImage.py
	modified:   Control.py
	modified:   FitsImage.py
	modified:   Settings.py
	modified:   ginga.py
	modified:   gtkw/FitsImageCanvasGtk.py
	modified:   gtkw/FitsImageGtk.py
	modified:   gtkw/GingaGtk.py
	modified:   gtkw/plugins/Pan.py
	modified:   gtkw/plugins/Pick.py
	modified:   gtkw/plugins/Preferences.py
	modified:   gtkw/plugins/Thumbs.py
	modified:   gtkw/plugins/Zoom.py
	modified:   qtw/FitsImageCanvasQt.py
	modified:   qtw/FitsImageQt.py
	modified:   qtw/GingaQt.py
	modified:   qtw/plugins/Pan.py
	modified:   qtw/plugins/Pick.py
	modified:   qtw/plugins/Preferences.py
	modified:   qtw/plugins/Thumbs.py
	modified:   qtw/plugins/Zoom.py
	modified:   util/mosaic.py
Fixes and enhancements to Ginga

	modified:   AutoCuts.py
	modified:   Control.py
	modified:   FitsImage.py
	modified:   Mixins.py
	modified:   Settings.py
	modified:   ginga.py
	modified:   gtkw/FitsImageGtk.py
	modified:   gtkw/GingaGtk.py
	modified:   gtkw/example1.py
	modified:   gtkw/example2.py
	modified:   gtkw/plugins/Info.py
	modified:   gtkw/plugins/Pan.py
	modified:   gtkw/plugins/Pick.py
	modified:   gtkw/plugins/Preferences.py
	modified:   gtkw/plugins/Thumbs.py
	modified:   gtkw/plugins/Zoom.py
	modified:   qtw/FitsImageQt.py
	modified:   qtw/GingaQt.py
	modified:   qtw/example1.py
	modified:   qtw/example2.py
	modified:   qtw/plugins/Info.py
	modified:   qtw/plugins/Pan.py
	modified:   qtw/plugins/Pick.py
	modified:   qtw/plugins/Preferences.py
	modified:   qtw/plugins/Thumbs.py
	modified:   qtw/plugins/Zoom.py

Various fixes and enhancements
- scaling to arbitrary values is exposed in Preferences
- some renaming to make consistent use of names (e.g. autolevels vs. autocuts)
- a new preferences/settings scheme to allow sharing of settings between
    FitsImage objects as well as a cleaner MVC-type interface to settings