Added Image Resizing to Scavenger Hunt

• User Images get downsized to fit screen.
• if initial screen content is too large to fit on small screen
devices, the lightning bolt logo will be downsized to fit screen (to
allow start button to fit).
• Added a check for duplicate images prior to downloading, to prevent
superfluous downloading.
Removed buggy duplicate removal code
Save Scaled images to File, Added in Scaling Up

•This will prevent repetitive rescaling when the user scrolls up and
down a long scavenger hunt list.
• Also, added in the ability to scale images up if they are less than
half the size of the allotted screen space.
Vertical scaling of images, centering grid view cells

• Added in scaling for tall, skinny images.
• set grid view to center images.
• added in a extra pixel of padding at top and bottom of grid view
cells.
added in a 10 pixel border around images and centered them
Added some padding code back into grid view
Merge branch 'Matt'