Merge pull request #1760 from francesco-cattoglio/issue_11713

added "dchar" for proper handling of UTF-8
Merge pull request #1763 from npadmana/typo_std_process_execute_doc

Fix completely trivial typo in std.process.execute documentation
Eliminate 'default' MODEL, instead compute from uname -m
Merge pull request #1765 from andralex/makefile

Eliminate 'default' MODEL, instead compute from uname -m
Move various deprecations along.
update onReceive documentation

Return value description was incomplete.
Merge pull request #1767 from gittywithexcitement/patch-1

update onReceive documentation
make non-ref opAssigns call the ref overload
change some ddoc comments to /++ Ditto +/
Add dependency control to posix.mak
remove spurious allocator targets
fix fileAttributes for Posix
Merge pull request #1770 from dawgfoto/fixup1751

fix fileAttributes for Posix
Merge pull request #1758 from e10s/issue11681

Fix Issue 11681 - std.datetime.IntervalRange.opAssign with non-ref parameter is required
mark std.zip classes as final
Fix Issue 11738 - partialShuffle should actually _be_ a partial shuffle :-)

This patch fixes the problem that partialShuffle was in fact invariably
shuffling the whole of the input, undetected because there were unittests
only for randomShuffle.

As well as the fix I've added some unittests specifically for partialShuffle
to ensure that it works properly, and I've taken the opportunity to tweak a
couple of bits of Ddoc and tidy up the randomShuffle unittests.
Got rid of expensive AddOrSubInt call (and related allocation).
Added description of logical (bitwise) operations.
fixup deprecation of externalAttributes

- directly access private member internally
- only deprecate the property
Removed unnecessary allocations in twosComplement call.