Default to foreground processing, background processing was eating errors & pacakges aren't necessarily installed in the 64-bit background environment.
push default urls out to class-level variable
use PIP8 variable name for output TIN
DRY out symbology naming
add any new url back to the valid filter list of URLs. fixes #5.
Add a new spatial reference parameter, to allow users to select output SR for datasets. Currently defaults to Mass State Plane.
Merge pull request #9 from scw/master

PEP8 improvements and a fix for adding URLs