Added SRS transformations to geotrellis.util.srs

-Added two Spatial Reference Systems (SRS), Web Mercator and Lat Long, and the transformations between them.
-Removed geotools dependency from geotrellis-server, the only thing being used for this was the reprojection capabilities of geotools. (Closes #567)

NOTE: Anything using the geotrellis.admin.Reproject object will now need to use the new method.
Remove geotrellis.admin.Reproject
Replaced catalog comment in reference.conf
Fix issue #574

Do not ignore item count when calculating median.  Median is
calculated similar to generateStatistics.
Merge pull request #569 from lossyrob/geotools-server-remove

Added SRS transformations to geotrellis.util.srs
Merge pull request #575 from ejc123/issue_574

Fix issue #574