Document poller hook POST request

The WebStatus Poller hook documentation did not mention POST requests.
POST allows use of cleaner curl -F option for poller parameter.
when unicode strings are passed as change_hook_auth parameters for WebStatus hooks (when using JSON files as configuration for example), the __init__ method fails, just fix that
Fix: unsubscribe StatusPush
Merge pull request #994 from kohtala/master

Document poller hook POST request
Merge pull request #997 from delanne/status_push_dont_unsubscribe

Fix: unsubscribe StatusPush
Merge pull request #992 from shoelzer/master

Add build steps for VC12, VS2013, and MsBuild12
using basestring as object to check for isinstance call on baseweb change_hook_auth
Merge pull request #996 from DamnWidget/#2605

[Fixes] For ticket #2605
Indicate that we don't use GitHub issues
Rename MsBuild to MsBuild4, add MsBuild alias for backward compatibility