Removing tmp files that accidentally got in initial commit
Unnecessary file for dompdf demo
Moving dompdf file to another location in next commit
Made plugin's uploads dir available to dompdf

Created a new class spdg_wp_constants to make the uploads directory path
available to dompdf. All tmp files are now written to the uploads
directory, for better or worse.
Added population of default values

Values didn't populate on first install. Also added so when left blank
they go back to their default values.
Fixed bug where uploads dir was not created on install