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
Fix issue 3363: std.stream.readf segfaults with immutabel format strings
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.)
Merge https://github.com/D-Programming-Language/phobos into issue-3363
Added unittest
Merge pull request #2224 from Hackerpilot/issue-3363

Fix issue 3363: std.stream.readf segfaults with immutable format strings
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`.