#12888: Fix a bug in HTMLParser.unescape that prevented it to escape more than 128 entities.  Patch by Peter Otten.

Structure field is not a string.

a string.

And "IDLE: fix some RessourceWarning, reuse tokenize.open()"

On error, call(), check_call(), check_output() and getstatusoutput() functions
of the subprocess module now kill the process, read its status (to avoid
zombis) and close pipes.

Suggested by Terry J. Reedy in #12298.

sigaltstack(2) doesn't work when linked with pthread.