make additional tests optional

- Remove them from the MANIFEST as they are
  not supposed to be distributed.
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.
hashOf: float portability fix
replace magic numbers with traits
more tests and comments
change termios structures to match glibc headers

removed termios2, termio, winsize. these seem to be kernel-level structures.
also, the termios expected by cfsetospeed, et al should have c_ispeed and
 c_ospeed.
Merge pull request #672 from IgorStepanov/hashoffix

hashOf: float portability fix
Revert "Move Linux stuff from ioctl to termios."

This reverts commit b1a28c1c33d756d7127a02968dd9763c2c3bfb4d.
ioctl needs termios2

termios2 has different NCCS than termios's termios.
just stick termios2 in ioctl I guess
constants for serial port speeds on linux
Merge pull request #671 from mylodon/termios-baudrates

constants for serial port baud rates
fix Issue 11478 - shared library on osx

- fix incomplete support for shared libraries
fix Issue 11653 - No error when forgetting break with range cases.
Merge pull request #680 from 9rnsr/fix11653

Issue 11653 - No error when forgetting break with range cases.
Merge pull request #677 from mylodon/termios-struct

change termios structures to match glibc headers
.gitignore Makfile
Merge pull request #682 from dawgfoto/gitignore

.gitignore Makfile
fix Issue 11674 - fenv_t declaration not architecture aware

- add declarations for X86 and X86_64
- also fix incorrect type for fexcept_t
Merge pull request #683 from dawgfoto/fix11674

fix Issue 11674 - fenv_t declaration not architecture aware