fixed #186 (can't duplicate blocks with anchored comments)
smooth numerical values displayed in watchers
Altered Snap! threading internals to allow for the same BlockMorphs to be used on different SpriteMorphs.

Processes are now created with a reciever, rather than taking the receiver from the top block.
This change was propagated through the call hierarchy.
Merge branch 'master' of https://github.com/Craxic/Snap--Build-Your-Own-Blocks