By changing to the Windows GetFileAttributes API in nt._isdir we can figure
out if the path is a directory without opening the file via os.stat. This has
the minor benefit of speeding up os.path.isdir by at least 2x for regular
files and 10-15x improvements were seen on symbolic links (which opened the
file multiple times during os.stat). Since os.path.isdir is used in
several places on interpreter startup, we get a minor speedup in startup time.

- Rename reST target name for collections ABCs to avoid collisions
- Add link to importlib ABCs (collections, numbers and io ABCs were already
  linked)
- Link to glossary entry from numbers module doc (other modules already do it)

test_multibytecodec_support. Improve also error message of the
test_errorhandle() of TestBase.

descriptor of a pipe closed in the parent process is valid in the child process
according to fstat(), but the mode of the file descriptor is invalid, and read
or write raise an error.

Add also requires_mac_ver() decorator to test.support.

constructor has failed, e.g. because of an undeclared keyword argument. Patch
written by Oleg Oshmyan.

iso2022_jp, iso2022_jp_2 and iso2022_kr

the following case: sys.stdin.read() stopped with CTRL+d (end of file),
raw_input() interrupted by CTRL+c.