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.
Merge in recent changes (split block improvements #619)
Add a new Favicon to Snap! (Clearer Lambda)

This is essentially the same icon (lambda, yellow w/ brown border) but newly
rendered at 64, 32, 24 and 16px for the best resolution on all platforms.
Fix "stop this block"’s lexical awareness

“stop this block” when used inside a custom block definition now always
returns out of the lexically enclosing script (the definition), even if
it is used inside other nested, C-shaped custom blocks in the
definition code. Previously it only stopped the nearest encompassing
“for” block, now it always stops the block whose definition it is in.
I don’t expect this fix to break any existing projects.
Fix “stop this block” primitive for tail-call-elimination
Fixed #318
Fixed #416
Fixed #372
Fixed #644
Fixed #34
fixed #131

and display an error if a reporter or a “called” ring is missing a
“report” statement
Merge pull request #652 from cycomachead/fav

Add a new Favicon to Snap! (Clearer Lambda)
Merge pull request #619 from cycomachead/split

Improvements to Split block for whitespace and line options
updated history
allow recursive reporters to be stopped by user
tail-call-elimination for reporters - experiment

(commented out, under construction)
Evaluator optimizations

reducing the stack size for reporters
Full TCO (tail-call-elimination)

now Snap! really *is* Scheme :-)
Fixed #656

make sure to always evaluate the “report” block’s input, even if used
inside a custom command definition, because hardware extensions (and
other reporters with side-effects) rely on it.
make the new favicon transparent