BUG Remove debug code
BLD Another important change for this release
BLD New release: 0.9.8

Full ChangeLog
	* Compute dense SURF features
	* Use matplotlib as IO backend (fallback only)
	* Fix sobel edge filtering (post-processing)
	* Faster 1D convultions (including faster Gaussian filtering)
	* Location independent tests (run mahotas.tests.run() anywhere)
	* Add labeled.is_same_labeling function
	* Post filter SLIC for smoother regions