• Remove include of windows.h from janet.h. This caused issues on certain projects.
• Fix formatting in doc-format to better handle special characters in signatures.
• Fix some marshalling bugs.
• Add optional Makefile target to install jpm as well.
• Supervisor channels in threads will no longer include a wasteful copy of the fiber in every
  message across a thread.
• Allow passing a closure to ev/thread as well as a whole fiber.
• Allow passing a closure directly to ev/go to spawn fibers on the event loop.