Add package libwebsockets

See #442 and #445.

Initial patch based on: Sergey <non_2001@mail.ru>

Modifications:
- fix update macro
- disable on MinGW32
- fix lib installation (w/o the patch it builds both shared/static)
- use system zlib

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
Add package intltool

See #445.

Signed-off-by: Timothy Gu <timothygu99@gmail.com>