Export details about skipped whitespace from C to Forth
Export details about skipped whitespace from C to Forth

Now it's possible for Forth code to query the scanner about two things
regarding whitespace:

* whether the last token parsed had a trailing delimiter, and if so, what it
  was (the word  trailing );

* how much whitespace was thrown away _before_ the last token parsed, and what
  it was (it can be pushed, like a string, by the word  skipped )

nickhen/muforth,nickhen/muforth