Issue #9290: In IDLE the sys.std* streams now implement io.TextIOBase
interface and support all mandatory methods and properties.
- Issue #15484: Fix _PYTHON_PROJECT_BASE for srcdir != builddir builds;
  use _PYTHON_PROJECT_BASE in distutils/sysconfig.py.
Issue #9290: In IDLE the sys.std* streams now implement io.TextIOBase
interface and support all mandatory methods and properties.
- Issue #16292: Improve a comment for cross building in configure.ac
Merge heads