linux support (read comments)

[alexqhj]

This should probably be in a new branch

This is only preliminary PR, because I don't know enough about electron and packaging to get it working properly. Hopefully someone can help build on this.

I don't have OSX so I can't vouch that it works there

1) Added my ide project folder to gitignore, because reasons, and updated all dependencies, so be sure it won't break OSX

2) Updated build scripts.

• Using new electron version for building
• Added new linux build command, not sure if best solution or to have one build command to build both. Again I don't know electron very well

3) Modified main.js

• Changed default shortcuts to windows/linux in case windows support would come at one point
• Added an OSX platform conditional that will hide the dock and change the shortcut commands (I hope this conditional works)

[niftylettuce]

@ahjorth @alwx Can you help merge this and test? Would love to add Linux support here.

Looking for more maintainers too! #13