Processing changes

* Fixed a bug where the output height and width of the array were swapped. 
* Added a command line flag to save the resize file
* Changed the resize temp file format to PNG.  The default jpeg codec was anti-aliasing the output.  
* Changed the resize method to "grid" as that seems to produce a better output.  This param should probably be a command line argument.
* Added const and PROGMEM compiler directives to the output array.  Again, this should probably be a command line argument
That'll teach me to test with square images!