Socket, connection handling changes

[gbakeman]

Attempting to troubleshoot lost connection problem in #223. This led to some significant changes in the socket communication code.

Enums: Removed noresponse enum, replaced with empty and unrecognized.

Socket:

• Modified Disconnect sub to have more concise parameter, remove unnecessary stream disposal
• Restructuring of core Query_Data subroutine. Moved or eliminated variable initialization, early sanity check for connection status, removed redundant newline in stream write, process response using .NET functions, move Enum parsing inline to subroutine, early check for null/empty response, distinct handling of good vs. bad results
• Removed unused Watchdog code (essentially became null/empty case in Query subroutine)
• Removed exception from Socket_Broken parameter

UPS:

• Stop variable update loop from calling Socket_Broken() (prevents duplicate triggers, the other being in Socket)
• In multi-variable get subroutine, only recurse on VARNOTSUPPORTED or STALE errors, everything else should be thrown.

Also includes a small bugfix that makes the connection menu command buttons sync their state when the connection is lost.