Janet 1.14.1

This release brings lots of improvements to the ev/ module, as well as bug fixes.

• Add doc-of for reverse documentation lookup.
• Add ev/give-supervsior to send a message to the supervising channel.
• Add ev/gather and chan argument to ev/go. This new argument allows "supervisor channels"
  for fibers to enable structured concurrency.
• Make -k flag work on stdin if no files are given.
• Add flycheck function to core.
• Make backmatch and backref more expressive in pegs.
• Fix buggy string/split.
• Add fiber/last-value to get the value that was last yielded, errored, or signaled
  by a fiber.
• Remove :generate verb from loop macros. Instead, use the :in verb
  which will now work on fibers as well as other data structures.
• Define next, get, and in for fibers. This lets
  each, map, and similar iteration macros can now iterate over fibers.
• Remove macro eachy, which can be replaced by each.
• Add dflt argument to find-index.
• Deprecate file/popen in favor of os/spawn.
• Add :all keyword to ev/read and net/read to make them more like file/read. However, we
  do not provide any :line option as that requires buffering.
• Change repl behavior to make Ctrl-C raise SIGINT on posix. The old behavior for Ctrl-C,
  to clear the current line buffer, has been moved to Ctrl-Q.
• Importing modules that start with / is now the only way to import from project root.
  Before, this would import from / on disk. Previous imports that did not start with . or /
  are now unambiguously importing from the syspath, instead of checking both the syspath and
  the project root. This is backwards incompatible and dependencies should be updated for this.
• Change hash function for numbers.
• Improve error handling of dofile.
• Bug fixes in networking and subprocess code.
• Use markdown formatting in more places for docstrings.