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)
Private module imports take precedence

For module Needs imports, give private module exports a
higher priority than runtime library (lib) imports. Doesn't
affect scripts, which use strict in-order precedence already.

See http://issue.cc/r3/1998 for details.
Merge pull request rebol/r3#101 (0branch/browse-macosx) into community

* 0branch/browse-macosx:
  Clean up browser calls for POSIX platforms.
  Implement BROWSE on Mac OS X.
Merge pull request rebol/r3#103 (BrianHawley/wish-1990-reword-rework) into community

* BrianHawley/wish-1990-reword-rework:
  REWORD API Revamp (See http://issue.cc/r3/1990)
Merge pull request rebol/r3#106 (0branch/block-to-binary) into community

* 0branch/block-to-binary:
  Ensure that binary series constructed from blocks are distinct
Merge pull request rebol/r3#110 (ladislav/bug#1989) into community

* ladislav/bug#1989:
  Collect unused GOBs Resolving bug#1989. Define new GOB_MARK and GOB_USED GC flags. Use the resv field to store GC flags.
Merge pull request rebol/r3#113 (gchiu/patch-2) into community

* gchiu/patch-2:
  do-redirect expects an absolute url so create one
Merge pull request rebol/r3#114 (BrianHawley/fix-1998-private-module-precedence) into community

* BrianHawley/fix-1998-private-module-precedence:
  Private module imports take precedence
Merge pull request rebol/r3#115 (earl/fix-2017-resolve) into community

* earl/fix-2017-resolve:
  Fix crash in RESOLVE/extend/only
Merge pull request rebol/rebol#76 (CCX/patch-1) into community

* CCX/patch-1:
  Update s-trim.c
  Update s-trim.c
  Update s-trim.c
  Minor tweaks
  Update s-trim.c
  Update src/core/s-trim.c
  Trim that Bug! (minor tweaks)
  Update src/core/s-trim.c
Merge pull request rebol/rebol#117 (earl/fix-2030-boot-flags) into community

* earl/fix-2030-boot-flags:
  Fix incorrect boot flags order
Merge pull request rebol/rebol#118 (earl/build-host-init) into community

* earl/build-host-init:
  Remove and ignore generated file src/boot/host-init.r
Merge pull request rebol/rebol#120 (ladislav/load#2041) into community

* ladislav/load#2041:
  Remove message print when LOAD/NEXT is used. bug#2041
Merge pull request rebol/rebol#121 (ladislav/valueq) into community

* ladislav/valueq:
  Let the VAUE? function yield #[false] for out-of-scope function variables, which is what the documentation describes. bug#1914
Merge pull request rebol/rebol#126 (ladislav/READMEpl) into community

* ladislav/READMEpl:
  Add an example of platform ID Add an example of make clean "make r3" can be used Rename REBOL to Rebol
Merge pull request rebol/rebol#127 (ladislav/sys-sys) into community

* ladislav/sys-sys:
  Delete unused header file
Reintegrate mainline into community

* master (of rebol/rebol):
  Added Greggs updated split from http://issue.cc/r3/1886
  Replace the debug makefile I accidentally commited on prior push.
  Add back debug build option for series labels and fix low level dump functions. With series labels enabled, using STATS will print a nice list of all series and identify some of the key series, or give you a clue about where they originated.
  HTTP: remove auto-decoding of UTF-8 content
  Simplify value? change (pull 121, cc 1914) by using existing function.
  Provide more info if make fails due to no local Rebol build tool.
Custom README to describe the Emscripten work-in-progress
Use {STDIN,STDOUT}_FILENO instead of 0, 1

Instead of referring to I/O streams (stdin, stdout) by hard-coded
integer file descriptors (0, 1), use the respective preprocessor symbols
(STDIN_FILENO, STDOUT_FILENO).

Originally suggested by user HostileFork on StackOverflow Chat.
Split up Host_Main into Host_{Init,Repl,Quit}