[Forge] Change compareTo() for commands to fix a Comparable contract issue.
Clean up Javadocs for the blocks.* package.
Code clean up, add preconditions, and correct Javadocs.
Rewrite session code and add support for persistent sessions.
Fix checkstyle error due to recent cleanup.
Fix undo and redo broken by a precondition.
Add Perlin, ridged multi-fractal, Voronoi noise generators via libnoise.
Add noise functions to the expression evaluator.
Update build files for noise library.
Add "=expression" mask.

i.e. =perlin(0,x/2,y,z/2,0.05,3,0.8)<0.1
Add noise library to allowed imports.
Refactor RegionSelectors so limits are passed in during selection.
Improve how //sel prints its available modes.
Fix ForgeWorld's equals() being very broken.
Add //sel -d <type> to set a default region selector type.
Clean up and removal of some old exceptions.
Fix Javadocs and code issues.
Fix some additional Javadoc errors.
Use -Xdoclint:none on JDK 8 and generate sources/Javadocs by default.
Remove <targetPath>.</targetPath> for resources.