New "theme selector" options page, updating build system and project structure

[scottalguire]

First off, I've been using this plugin for years and I have really enjoyed not being blinded by the default white devtools, so thank you!

Recently I decided to adapt my current favorite syntax theme "Panda" for devtools.

After adding the new theme, I realized it would be cool to switch themes without having to:

• git clone the repo
• update config
• npm install
• run grunt
• reload the unpacked extension
• etc.. it's a whole lot of ceremony

For that reason I've updated the plugin so that themes can be switched from an options panel, with the current option being stored in chrome storage.

Other changes are listed below and (in the changelog)

• Added Panda Syntax theme by @siamak
• Added new extension options popup for switching themes without leaving Chrome
• Remove hardcoded stable version in favour of API call
• Updated project structure and build setup to accomodate theme switching
• Added JSON file for controlling options panel
• Added missing variables to older themes that were failing to compile

Here is what the options panel looks like:

I'm happy to address any questions/suggestions

Cheers

[mauricecruz]

Wow, thanks for doing this! Really impressive work! Always planned on creating a UI loader, but kept kicking that can down the road.

I'll give it a lookover this week.