gui_qt: Add open config folder action

[nsmarkop]

Fixes #697.

I added an entry for "Open config folder" to the File menu that opens up the configuration folder.

The icon used is from Icons8 Flat Color Icons.

Perhaps the oddest part here is the use of webbrowser.open to open the folder. os.startfile is Windows exclusive, so I searched around for cross platform ways to open folders and files and ended up on that standard library function accomplishing the desired behavior despite the name. Alternatively something like this could be implemented, but I figured if webbrowser.open works it's simpler to rely on it:

import subprocess, os
if sys.platform.startswith('darwin'):
    subprocess.call(('open', filepath))
elif os.name == 'nt':
    os.startfile(filepath)
elif os.name == 'posix':
    subprocess.call(('xdg-open', filepath))

I've only verified behavior on Windows, so Mac / Linux testing would be nice.

[benoit-pierre]

Seems to work fine on Linux.

[benoit-pierre]

@morinted: can you check it works on macOS?

[TheaMorin]

Yes -- will check in 36 hours when I have my Mac again.

[TheaMorin]

On initial go, this doesn't do anything on macOS. I'll try the PyQT update and see if that makes a difference as I'm on the current macOS version (10.14)

[TheaMorin]

After updating to the requirements in #1023, this still doesn't work :( might have to go with the OS-switch after all.

[nsmarkop]

Darn. Since it doesn't seem to work for you on Mac, I updated the logic to be platform-specific instead. I only tested on Windows so I'll need verification again for Linux / Mac on this approach.

[TheaMorin]

Works for me on Mac

[benoit-pierre]

I think you can remove the mention, as testing it again on Linux with my configuration, I see that it always open a directory listing in my browser, which is clearly not the best behaviour.

[nsmarkop]

Removed in the latest commit.

[benoit-pierre]

For Python 3.4 compatibility:

Suggested change

	subprocess.run(['xdg-open', CONFIG_DIR])
	subprocess.call(['xdg-open', CONFIG_DIR])

[nsmarkop]

Updated this in the latest commit.

[benoit-pierre]

Works fine on Linux.

[benoit-pierre]

Looks like the Circle CI build is not run on the result of the merge, but directly the PR branch, unlike AppVeyor / Travis...