Squashed commit of the following:

commit ca3fbe2ff9d07162e4cc4488f4280f0b189f86e8
Author: Luke Campagnola <luke.campagnola@gmail.com>
Date:   Thu Aug 7 08:41:30 2014 -0400

    Merged numerous updates from acq4:
    * Added HDF5 exporter
    * CSV exporter gets (x,y,y,y) export mode
    * Updates to SVG, Matplotlib exporter
    * Console can filter exceptions by string
    * Added tick context menu to GradientEditorItem
    * Added export feature to imageview
    * Parameter trees:
        - Option to save only user-editable values
        - Option to set visible title of parameters separately from name
        - Added experimental ParameterSystem for handling large systems of
            interdependent parameters
        - Auto-select editable portion of spinbox when editing
    * Added Vector.__abs__
    * Added replacement garbage collector for avoiding crashes on multithreaded Qt
    * Fixed "illegal instruction" caused by closing file handle 7 on OSX
    * configfile now reloads QtCore objects, Point, ColorMap, numpy arrays
    * Avoid triggering recursion issues in exception handler
    * Various bugfies and performance enhancements
Fixes following acq4 merge
Disable image downsampling when n=1
Remove old PIL-fix files, replace with equivalent runtime-patching code.