XSB Src (SVN)-old

Explicit casts to quiet persnickety compiler.

Added some casts (and some slightly different type decls) to quiet
warnings in MSVC on Windows 10.

Changed way to find current windows system in order to get tome. (Old
way deprectaed and this is suggested new way.)

Fixes to hopefully get XSB to compile on Windows with message queues.
I commented out the mq locks for the sequential Windows version.

Also, some code to enable MQs to be called from C.

Ifdeffed the use of mutex attributes for Windows.

Implemented interrupts with goals for sequential engine -- an analog
of thread signal queues. Curr_sym.* is other setup for tripwires, which wont interfere with anything.

Implemented version of message queues for single-threaded engine, to
support interrupts with general goals.

Added interrupt_with_goal and handle_goal_interrupt. These allow a
computation to interupt itself from Prolog with any goal.

Fixed minor bug in timed_call test.

Fixing xsb testsuite for MT