remove DOCS from default target and druntime.zip

- These are the raw b&w ddoc html files that nobody uses.

- The distributed druntime docs are generated
  by dlang.org (through the doc target).
move -version=CoreDdoc to DDOCFLAGS

- DOCFMT is typically overriden when calling
  the makefile.
fixup #674 - should test .length instead of .ptr
Fix Issue 4483 - foreach over string or wstring, where element type not specified

core.demangle does not support Unicode and iterates over ASCII only.
add unittest for finalization during library unload
finalize objects whose shared library is about to be unloaded
lazier generation of stack traces
the throwing function was left out!
Revert "the throwing function was left out!"

Oops, turns out the default handler leaves it out too so this was
correct the first time.

This reverts commit f715ecdc335127508b3eed36c20d320f388a375e.
fix Issue 12121 - atomicLoad!(MemoryOrder.acq) doesn't require load barrier

[Issue 12121 – atomicLoad!(MemoryOrder.acq) should not emit additional code on X86](https://d.puremagic.com/issues/show_bug.cgi?id=12121)
Merge pull request #667 from MartinNowak/rmDOCS

[install] remove DOCS from default target and druntime.zip
Merge pull request #723 from MartinNowak/fix12121

fix Issue 12121 - atomicLoad!(MemoryOrder.acq) doesn't require load barrier
Fix typo in aa pointer rehash
Merge pull request #726 from yebblies/moreaafix

Fix typo in aa pointer rehash
other comments on github
Merge pull request #717 from adamdruppe/exception_speed

lazier generation of stack traces
Fix issue 11519 - race in core.thread unit test
Merge pull request #728 from Safety0ff/fix11454

Fix issue 11519 - race in core.thread unit test
First set of stdc changes for Android
Fix formatting