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.
no need to GC scan the .rodata segment

- Also _deh_end will have to live in .data for PIC code
  (Bugzilla 11171), so it can't be used as end of .rodata.
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.
Merge pull request #715 from MartinNowak/dontScanRODATAonFBSD

[dll] FreeBSD must not GC scan .rodata
Replace AssociativeArray struct with UFCS methods
Merge pull request #668 from yebblies/fixaarray

Replace AssociativeArray struct with UFCS methods
Fix for issue 11981
Switch to using pthread_key_t for Thread reference on Posix
Use atomic ops in host test
pthread_key_delete(); Don't use pthread_key_t on OSX
missing else
Merge pull request #719 from radcapricorn/host_test_atomic_ops

DRuntime: Use atomic ops in host test
Merge pull request #718 from radcapricorn/issue_11981

Fix for issue 11981 - deadlock during thread initialization on Posix