Fix bug 7648 comment in `std.stdio.File` and add bug section to `std.file.slurp`.

Issue URL: http://d.puremagic.com/issues/show_bug.cgi?id=7648
std.math: Check if dmd-style inline asm is available
Fix Issue 13042 - std.net.curl.SMTP doesn't send emails with libcurl-7.34.0 or newer
Start getting tests passing on Android/x86
Fix issue #13100 - std.process.setCLOEXEC() throws

There are two cases in which the fcntl() calls may fail:

  1) the file descriptor is invalid, in which case errno == EBADF,
  2) they receive invalid arguments, in which case errno == EINVAL.

We just want to ignore the error in the former case, as evidenced by
the bug report, and the latter means that we have an error in
std.process, which is best handled by an assertion. (Note that it was
never possible to catch the exception anyway, since it was thrown in
the child process.)
Add method for std.net.curl.HTTP that allows user to specify Content-Type.
Merge pull request #2326 from kyllingstad/no-setcloexec-fail

Fix issue #13100 - std.process.setCLOEXEC() throws on invalid file descriptor
Merge pull request #2150 from joakim-noah/android

Get tests passing on Android/x86
Merge pull request #2307 from brocolis/fix13042

Fix Issue 13042 - std.net.curl.SMTP doesn't send emails with libcurl-7.34.0 or newer
Merge pull request #1653 from denis-sh/fix-bug-7648-comments

Fix bug 7648 comment in `std.stdio.File` and add bug section to `std.file.slurp`.
Merge pull request #2133 from jpf91/mingw

std.math: Check if dmd-style inline asm is available
Expand ddoc.
Merge pull request #1527 from quickfur/post_contentType

std.net.curl: Allow user to specify Content-Type in POST requests