fixed #119, #149

accessing a shared projects requires lowercasing the username - this is
now automatically taken care of
Merge pull request #163 from MMSequeira/master

Portuguese translation update
fixed part of #154 - prevent costumes from being drawn while they are loading

prevents an occasional DOM error saying "an attempt was made to use an
object that is not, or is no longer, usable" when loading a project
that has costumes
prevent costumes with imported CORS-tainted canvases

expected to fix #155, #154, #151, #148, #147, #127 for future projects
Prevent local custom blocks in global custom block definitions

fixes #167 for future projects
fixed #169
fixed #146

filter out empty costumes
fixed #172, IF ON EDGE, BOUNCE

Morphic: Rectangle.amountToTranslateWithin()
fixed #186 (can't duplicate blocks with anchored comments)
smooth numerical values displayed in watchers
Type-check the SPLIT block's input before eval'ing it
Prevent watcher cells from growing wider as their contents becomes taller
Keep watchers onstage when hiding/showing them, fixes #195
"plain block prototype labels" preference setting

hide / show the (+) symbols in the block editor
fixed type-issue for linked list indices

thanks, Nate, for reporting this issue
experimental MAP primitive reporter

in lists category, visible in dev mode for now
fixed #199

"can't delete reporter with attached comment via context menu"
MAP primitive variant for linked lists
"sanity check" for cloud-saving mechanism

errors if the serialized project data is corrupt and cannot be parsed
as XML, addresses #203, #200, #171. I'm hoping that this might provide
us a clue whether the corruption is happening in Snap's marshalling or
on the backend side