Fixed #55
Creating a variable which already exists no longer performs any action.
Fixed #53
Renaming a script variable presents a dialog entitled "Script variable name," while renaming a ring input still presents a dialog entitled "Input name"
Fixed issue #27
The "Import tools" menu item no longer has an ellipsis.
Updated translations to reflect "Import tools..." -> "Import tools"
Fixed #59
The "Export tools..." and "Export project as plain text..." menu items no longer have a space before their trailing ellipses.
Fixed #19
Blocks highlights now retain the correct color when their associated stacks are dragged elsewhere.
Fixed #23
Only one of each kind of dialog can now be open at any given time.

You can still open multiple dialogs for editing a costume and editing a block.
Fixed #72

Canceling a "Save as..." operation will no longer replace the selected project upon the next save.
Fixed #44

Circularity no longer breaks watchers
Merge pull request #57 from queryselector/issue-55

Fixed #55
Merge pull request #58 from queryselector/issue-53

Fixed #53
Merge pull request #60 from queryselector/issue-27

Fixed #27
Merge pull request #61 from queryselector/issue-59

Fixed #59
Merge pull request #68 from queryselector/issue-19

Fixed #19
Merge pull request #76 from queryselector/issue-72

Fixed #72
Merge pull request #74 from queryselector/issue-23

Fixed #23
Release clean-ups & translation update
Fine-tune multiple dialog instance handling

prevent multiple block editors on the same block definition, allow
multiple dialogs on different objects, handle dialog instances in
DialogBoxMorph.prototype
Hide Primitives feature

Primitive blocks in the palette can now be hidden in the project via
their context menu. Each palette's context menu further lets you hide
or show all its primitives depending on whether any primitives are left
to hide or show.
Hidden primitives are stored in the project data. This lets instructors
create "simplified" examples and problem sets.
Restore multi-dialog restrictions for multi-world setups