Showing missing vocabulary in EBL_TREEBANK

A trivial but rather useful little feature I just added: when you run EBL_TREEBANK, you now get missing vocabulary displayed for relevant sentences. I don't know why I didn't do this years ago. Here's an example. To get the new functionality, you just need to update Regulus from CVS, nothing needs to be remade.

>> EBL_TREEBANK
(Parse all sentences in current EBL training set into treebank form)

--- Read parsing history file (114 records) d:/cygwin/home/speech/regulus/examples/shrd2/generated/shrd2_parsing_history.pl
--- Incremental treebanking switched off, not trying to convert treebank

Parsing corpus data in d:/cygwin/home/speech/regulus/examples/shrd2/corpora/shrdlu_corpus.pl:
..
*** Parsing failed for: "find a block which is taller than the one you are holding and put it into the box", line 2
...
*** Parsing failed for: "is at least one of them narrower than the one which i told you to pick up", line 6
Words not in current vocabulary: [told]
.....
*** Parsing failed for: "will you please stack up both of the red blocks and either a green cube or a pyramid", line 12
Words not in current vocabulary: [either]
...