REWORD API Revamp (See http://issue.cc/r3/1990)

Requested changes (requester):
* Binary support, and working tag support (BrianH)
* /case for case-sensitive comparison (BrianH)
* Specifying leading and trailing delimiters with /escape (i.e. for
HTML/XML entities) (BrianH)
* Being able to specify none as an /escape, equivalent to "" now
(HostileFork)
* Evaluating value expressions directly in a block spec, rather than
requiring the spec to be reduced, and /only to turn that off
(rgchris, BrianH, prompted by GrahamChiu's RebolBot code)
* Evaluating block values as code like functions, to cut down on
function
creation overhead, and /only to turn that off (rgchris)
* Special-case treatment of set-word keys as if they were regular words,
so block and object specs can be compatible (BrianH)
* Special-case treatment of lit-word keys as if they were regular words,
to be compatible with fully reduced specs (BrianH)
* Directly using values specs that already match what we need
internally,
to save overhead (BrianH)
* Better-phrased doc strings that are short enough to not wrap on the
Windows console (BrianH)
Merge pull request #103 from BrianHawley/wish-1990-reword-rework

REWORD API Revamp (See http://issue.cc/r3/1990)