Release 4.1.5

This is a minor maintenance release, mostly addressing behaviour around process shutdown and startup, along with a couple of small enhancements that most users won't notice.

• If there is already an EDMarketConnector.exe process running when trying to run another instance then that new process will no longer exit silently. Instead you'll get a pop-up telling you it's detected another process, and you need to close that pop-up in order for this additional process to then exit.

  This hopefully makes it obvious when you've got a hung EDMarketConnect.exe process that you need to kill in order to re-run the program.

• In order to gather more information about how and why EDMarketConnector.exe sometimes doesn't shutdown properly we've added some extra debug logging to the sequence of clean-up calls performed during shutdown.

  Also, to make it more obvious if the process has hung during shutdown the UI window is no longer hidden at the start of this shutdown sequence. It will instead linger, with "Shutting down..." showing in the status line (translation for this small phrase will be added in a later release).

  If you encounter this shutdown hang then please add a comment to Application can leave a zombie process on shutdown #678 to help us track down the cause and fix it.

• Cater for 'mangled name' class functions in our logging code. e.g. where you name a class member with a __ prefix in order to 'hide' it from out-of-class code.

• To help track down the cause of Crashing On Startup #798 we've added some exception catching in our logging code. If this is triggered you will see ??:?? in logging output, instead of class and/or function names.

  If you encounter this then please comment on that bug report to aid us in tracking down the root cause!

• Fixed logging from EDMC.exe so that the -debug log goes into EDMC-debug.log not EDMarketConnector-debug.log.

• Fix EDMC.exe -j handling of file encodings. NB: This command-line argument isn't listed on EDMC.exe -h as it's intended for developer use only.

• Fix the name of 'Void Opal(s)' so that output of market data to files is correct.

• Fix URL in PLUGINS.md to refer to main, not master branch.

• We're able to pull py2exe from PyPi now, so docs/Releasing.md has been update to reflect this.