Fixes #2448 (tab wrapping in Japanese). Also ensures that none of the Sprite info area wraps. Does not address the issue where the sprite info area is too big and pushes the stage info off the screen.

Also remove some obsolete code

Fixes #1955

* Player mode

Add isPlayerOnly property on GUI. Move isFullScreen into mode reducer with isPlayerOnly.

Full screen needs to be a separate prop so that GUI knows what to show when exiting full-screen (either player-only or full editor).

- set `gui-body * {box-sizing: border-box;}` instead of expecting it to be set by the enclosing component/playground, and removed uses of content-box (adjusting sizes as needed) 
- Added `!isPlayerOnly` to the conditions for draggable sprites
- rewrote player example to use player mode.

Question, should ‘x’ and ‘y’ be localizable?

- Auditing color CSS and componet CSS to make consistent.
- Made a first pass of changes to increase contrast to elements that previously were problematic

This reverts commit 0a741b10.

Should help with smaller screen sizes, where the ratio is different (like some chromebooks)

Fixes https://github.com/LLK/scratch-gui/issues/1064

With jscodeshift thank God

Fixes #156 + refactored classnames to style guide conventions

Affects SpriteSelector Pane, StageSelector Pane, Stage, MenuBar, Libraries Modal, Add/Import buttons, for Chrome, Ffx + Safari on Sierra.

Fixes #162