Forward-port all missing changes from mainline rebol/rebol to Ren/C

[earl]

This pull request incorporates all (except one) missing changes that were previously applied to mainline rebol/rebol but up to now missing from Atronix (and then mostly removed from Ren/C during the Atronix merge).

The following three pull requests were missing completely:

• Fixes FUNCTION and CLOSURE when /local not last refinement rebol/rebol#186 (BrianHawley/fix-2109-function-local-not-at-end)
• Get rid of RETURN/redo rebol/rebol#198 (BrianHawley/wish-2121-no-return-redo)
• Fix word hash collision and function parameter type mismatches rebol/rebol#193 (BrianHawley/fix-2113-hash-collision)

Parts of the following six pull requests were missing (mostly just comment changes):

• Get rid of if/else rebol/rebol#185 (BrianHawley/wish-2077-no-if-else)
• Fix CATCH/quit interaction with TRY (cc#851) rebol/rebol#167 (earl/fix-851-try-catch-quit)
• Fix SHIFT CC#2067 rebol/rebol#149 (ladislav/shift)
• Use David M. Gay's STRTOD instead of system specific atof(). rebol/rebol#144 (ladislav/STRTOD)
• FUNCTION and CLOSURE revamp (#1973 and #2002) rebol/rebol#109 (BrianHawley/wish-1973-function)
• Fix WAIT polling interval on POSIX platforms rebol/rebol#168 (earl/fix-posix-wait-rate)

Finally, the one exception, which is not contained in this pull request. The following change was merged but then reverted in Atronix:

• FIND-ALL speed optimization rebol/rebol#183 (BrianHawley/wish-2005-find-all-speedup)

Also see zsx#26 for the corresponding pull request submitted to Atronix.

[hostilefork]

Great! Merged and on we go...