Added few missed tests for configure options.

Force clean of externals on buildbots.

The bufsize parameter is no longer used.

On Windows a symlink can has the FILE_ATTRIBUTE_DIRECTORY flag.

On Windows a symlink can has the FILE_ATTRIBUTE_DIRECTORY flag.

gcc as the option does not work correctly in older versions of gcc
and has been silently removed as of gcc-4.5.

Patch by Alex Willmer.

Since Python 3.4, there is no need to install pip and setuptools
into a venv manually.

Patch by Guo Ci Teo.

Raise ValueError if algorithm is not MD5 or SHA.

Initial patch by Mathieu Dupuy.

Patch by Liang-Bo Wang.

Patch by Liang-Bo Wang.

Issue #25888

Patch by Sebastien Bourdeauducq (issue #26338)

Patch by Frederick Wagner (issue #26347)

Patch by Chris Angelico (issue #26221)

Patch by Vladimir Rutsky.

Initialize i variable if the string is non-ASCII.

Issue #26464: Fix str.translate() when string is ASCII and first replacements
removes character, but next replacement uses a non-ASCII character or a string
longer than 1 character. Regression introduced in Python 3.5.0.

when resulting prefix length is equal to maximal prefix length.
Based on patch by Xiang Zhang.