Fixes to various stream cast on win64

This fixes further issues on win64 with casts from the streams.
Sockets/descriptors handling was unitized. This has an impact only on
win64, php_socket_t otherwise can be feed back to int datatype.
remove obsolete comment
Merge branch 'PHP-5.6'

* PHP-5.6:
  remove obsolete comment
  Fixes to various stream cast on win64