ij-plugins Toolkit v.1.3.0

New Features:
* Seeded Region Growing (SRG) plugin

Improvements:
* Fast Median Filter plugin – added preview to options dialog.
* Code cleanup and removal of unused/obsolete classes.

Bug fixes:
* BUG-2687379: Division by zero in entropy threshold progress reporting.
Pointed by Gabriel Landini.
* Correct potential numeric computation problem in maximum Entropy threshold
pointed by Wilhelm Burger. EPSILON is made larger to avoid infinite result
when dividing by values close to EPSILON.
* BUG-2690849: Multiband Difference Edge and Multiband Gradient Edge plugins
were missing.

Other:
* Project code moved to Java 1.6.
* API for display of multi color overlays (OverlayCanvas)
* I/O Utilities API (IOUtils)