Tool changes saved in  preferences

Starting from a fresh pull from github master, a few small changes.

Commit 0b266d8 made it so I could compile and run from eclipse.  Moves the limits.png image out of bin and into src.

Commit 65abec7 is the real point.  It saves tool configurations in preferences and fixes some type (String/Float/Long) issues with that.

Commit da5678a adds some generic type parameters to get rid of some compiler warnings.