Forth related improvements for etags

Forth related improvements for etags

Generate correct tags names for things like "(foo)".
Previously "(foo" created.

Fix a bug where a tag for "-bar" was created when encountering things
like "create-bar".

Recognize more words from the Forth-2012 Standard.

* lib-src/etags.c (Forth_words): Check for whitespace after defining
words.  Create tag with make_tag instead of get_tag to avoid notiname
which isn't appropriate for Forth.

* test/manual/etags/forth-src/test-forth.fth: Add some test cases.
* test/manual/etags/ETAGS.good_1:
* test/manual/etags/ETAGS.good_2:
* test/manual/etags/ETAGS.good_3:
* test/manual/etags/ETAGS.good_4:
* test/manual/etags/ETAGS.good_5:
* test/manual/etags/ETAGS.good_6:
* test/manual/etags/CTAGS.good: Adapt to the changes in etags.c and
new test cases.