Add Windows Support

[iamfraggle]

Some fixes to errors that occur on Windows:

• Use uri.fsPath instead of uri.path to get the working directory in OS-specific format
• Escape quote characters inside command strings
• Use magic text (similar to 'VSCode' pretty format) to represent stash refs so they can be evaluated in a separate step - Windows Command Prompt does not understand $(git ...) expressions and has no equivalent.

[phil294]

wow, that's all it took? amazing!

thanks for tackling this! :-) I will quickly test this out on Linux tomorrow and then make a new release.

I was also thinking of perhaps replacing the ascii graph chars with svg lines (opt-out), but I probably won't include that in the same build.

[phil294]

one small adjustment needed. Could you change that?