While working on the menubar, I couldn't find the source of an error. This adds more stack info to the error messages emitted by the error boundary.

Update default project with new more compact serialization.

Add costume size/sound length details to sprite tile and update styling

Update scratch-paint to the latest version 

Fixing issue #1753

Update VM manually in package json

Remove camera upload options from sprite and backdrop selectors.

Fixes for load button issues.

chore(package): update scratch-paint to version 0.2.0-prerelease.2018…

chore(package): update scratch-blocks to version 0.1.0-prerelease.152…

Phase 1 - Audit/Update GUI Colors

Closes #1746

Closes #1737

Updates include modifications to interaction states for the following: tabs, add menus, forms, and stage selector.

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

Remove toString call in the project-loader.

Fix handleExtensionAdded when no targets present

Manually fire tab change events onclick to fix touching tabs not working

Merge pull request #1733 from LLK/greenkeeper/scratch-vm-0.1.0-prerelease.1523023502-prerelease.1523023526

Update scratch-vm to the latest version 

It seems like there is some kind of touch action interference coming
from the blocks panel, where if you touch the tabs on a touchscreen
chromebook/chrome responsive mode, it does not select the tab if the
touch radius is overlapping the blocks panel at all. See gifs in PR for
more explanation. Fixes issue #1283, making chromebooks useable!

Merge pull request #1729 from LLK/greenkeeper/scratch-vm-0.1.0-prerelease.1522969014-prerelease.1522969034

Update scratch-vm to the latest version