0.5.6

Added:

• New core utility function aliases (written in pure Python) are now
  available in xonsh.xoreutils. These include: cat, echo,
  pwd, tee, tty, and yes. These are not enabled by default.
  Use the new coreutils xontrib to load them.

• CircleCI test post codecov run

• The trace will automatically disable color printing when
  stdout is not a TTY or stdout is captured.

• New jedi xontrib enables jedi-based tab completions when it is loaded.
  This supercedes xonsh's default Python-mode completer.

• The lexer has a new split() method which splits strings
  according to xonsh's rules for whitespace and quotes.

• New events for hooking into the Python import process are now available.
  You can now provide a handler for:

  • on_import_pre_find_spec
  • on_import_post_find_spec
  • on_import_pre_create_module
  • on_import_post_create_module
  • on_import_pre_exec_module
  • on_import_post_exec_module

Changed:

• The prompt toolkit shell's first completion will now be the
  current token from the auto-suggetion, if available.
• Sourcing foreign shells will now safely skip applying aliases
  with the same name as existing xonsh aliases by default.
  This prevents accitidentally overwriting important xonsh standard
  aliases, such as cd.

Fixed:

• Threadable predicition for subprocesses will now consult both the command
  as it was typed in and any resolved aliases.
• The first prompt will no longer print in the middle of the line if the user has
  already started typing.
• Windows consoles will now automatically enable virtual terminal processing
  with the readline shell, if available. This allows the full use of ANSI
  escape sequences.
• On the Windows readline shell, the teb-completion supression prompt will no
  longer error out depending on what you press.
• Fixed issue with subprocess mode wrapping not repecting line continuation
  backslashes.
• Handle a bug where Bash On Windows causes platform.windows_bash_command()
  to raise CalledProcessError.
• Fixed issues pertaining to completing from raw string paths.
  This is particularly relevant to Windows, where raw strings
  are instered in path completion.
• Replace deprecated calls to time.clock() by calls to
  time.perf_counter().
• Use clock() to set the start time of _timings in non-windows instead
  of manually setting it to 0.0.
• The trace utility will now correctly color output and not
  print extraneous newlines when called in a script.
• The @$(cmd) operator now correctly splits strings according to
  xonsh semantics, rather than just on whitespace using str.split().
• The mpl xontrib has been updated to improve matplotlib
  handling. If xontrib load mpl is run before matplotlib
  is imported and xonsh is in ineteractive mode, matplotlib
  will automatically enter interactive mode as well. Additionally,
  pyplot.show() is patched in interactive mode to be non-blocking.
  If a non-blocking show fails to draw the figre for some reason,
  a regular blocking version is called.
• Fixed issues like timeit ls causing OSError - "Inappropriate ioctl
  for device".
• Fixed a potential "OSError: [Errno 22] Invalid argument" to increase job
  control stability.