workaround for some REPORT / STOP BLOCK issues

enables reporting and stopping a bock from within a C-shaped slot in a
custom block, but not (yet) out of nested C-shaped custom blocks (but
that’s coming up, too)
fixed #599

disable IDE keyboard shortcuts in presentation mode
add localization to default costume name
add localization to default project name
correct errors in Portuguese translation and add translated strings
fixed #601

correctly display symbol for %obj type input slots in the prototype
template
Merge pull request #600 from MMSequeira/master

Corrections and additions to Portuguese translation
updated history
New feature - minimal stage mode (shift-click on small-stage button)
allow only numbers to be reported as number (fix #458)
leave a mark on pen down (fix #209)
show an error message if project cannot be loaded (fix #190)
don't leave a mark on pen down but on MOVE 0
fixed #604. Thanks, @Gubolin!
Fixed range 1 slider bug issue # 301
fixed #608, #610
Merge remote-tracking branch 'origin/master' into slider_range_one
add localization to unknown variable error
correct translation of 'unshare'; add new translations
Improvements to Split block for whitespace and lines:

* Split by whitespace now uses the built-in definition of whitespace \s
  This catches all characters definted as whitespace, see below:
  https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp
* Split a line by all unicode compliant line breaks. The biggest impact here is
  that OSX and Windows files will now split the same way.
The cr option is still around, but ther's no longer a need for it, IMO.