Japanese translations update

thanks to Kazuhiro Abe!!
Project Sharing / Unsharing Support (frontend)

Support for publishing and un-publishing projects in the cloud (not yet
live in the current production version of the cloud backend)
Anchored Comments Enhancements

* the Block Editor now allows anchored comments,
* duplicating a block / script / sprite now also duplicates anchored
comments,
* deleting a block / script now also deletes anchored comments
Fix: Removed added textarea from YPR module

No more text area in upper left corner of the Snap! IDE when converting
a .ypr project
PrototypeHatBlocks accept anchored comments

You can now "stick" comments to the prototype hat block in the block
editor
Loading shared cloud projects in presentation mode

and exporting URLs for shared projects
Display Custom Block Comments as Help

Selecting "Help" for a custom block now pops up the comment attached to
its definition's prototype hat, if any
Fix: Make Comments Detachable from Prototype Hats
Variable-names drop-down menu when renaming blobs

renaming variable blobs now features a drop-down menu in the dialog box
with reachable variable names and a picture of the block to be renamed
Correct and add translations strings for Portuguese translation.
Sharing / Unsharing projects finalization
Merge pull request #14 from MMSequeira/master

Improvements to the Portuguese translation
Adjust list watcher size to blocks' zoom scale
Italian translation update

Thanks for this constribution, Stefano Federici!
Fix: switch to edit mode and tab to scripts when loading a project
Turn pen trails into new costume

currently still hidden in the stage's context menu, visible when
shift-clicked
Removed .DS_Store and added a .gitignore
Fixed a number of whitespace inconsistencies
Fixed #3
When a locale is loaded with #lang:xx, the names of the new project and the sprite it contains are now localized
Fixed an encoding issue