Ditz issue update
Fix (mostly) gcc -O4 related compile warnings

Unused variables in some option combinations.  Some of these were caused by
having -DDUK_OPT_DEBUG but no debug print options.

The GCC -O4 array subscript warning seems spurious and is probably caused by
GCC not being 100% sure 'count' is always valid.  The call sites for
duk__advance_chars() have a variety of argument values, including those
computed using shifts etc.  Add an explicit check for the valid range which
silences the GCC error.  The check also protects against regressions that
would cause an invalid count to be used.  With the check in place,
potentially memory unsafe behavior will now cause an internal error instead.

If the form DUK_ASSERT(x >= 0 && x < y) is used, gcc will cause a spurious
warning:

    duk_api_stack.c:149:33: error: assuming signed overflow does not occur when assuming that (X - c) > X is always false [-Werror=strict-overflow]
    duk_error.h:131:8: note: in definition of macro ‘DUK_ASSERT’

By breaking down the assert into two, i.e. DUK_ASSERT(x >= 0) and
DUK_ASSERT(x < y) the warning disappears.
Merge branch 'fix-compile-warnings'

Fix some compile warnings mostly related to GCC -O4.  The GCC -O4 result is
not clean when assertions are enabled; the remaining warnings seem spurious
and difficult to silence in a reasonable way.
Matrix compile hack test
Merge branch 'matrix-compile-test'

Quick hack test for a mstrix compile test.  This rudimentary test revealed a
few compile warning issues which are fixed separately.

For proper coverage the test matrices will be very large, so a random
sampling approach is probably the most useful to quickly go through a lot of
variations.  The test matrix could then include basically every compiler and
feature option in isolation (creating billions of combinations) as well as
every testcase Duktape has.  For a given test matrix configuration one integer
can be used to identify a combination and easily report and repeat failures.
Release notes 1.0.0 draft
Merge branch 'release-notes-v1.0.0'

Add (draft) release notes for the 1.0 release.  The intent is for the release
notes of a stable version to be up-to-date so one can see known issues and
workarounds at a glance.
Ditz issue update
Add matfix test to release checklist
Merge branch 'update-release-checklist'
Add raw testcase runs to 1.0 known issues
Merge branch 'known-issues-test262-etc'
Trivial comment fix
Merge branch 'initjs-comment-trivia'
Threading link to limitations
Merge branch 'guide-limitations-threading-link'
Remove dollar escape as RegExp limitation

This feature is intentional and there's actually need for more real world
compatible behavior for RegExps.
Remove finalizers from Lua comparison section

Lua 5.1 does have finalizers in the form of the __gc metamethod (which only
works for userdata objects).
Weak references to Lua comparison
Merge branch 'guide-limitations-luacomparison-cleanups'