Added center alignment to the slide components
Vertical and horizontal center alignment through 2 icons added to the left and top tools on the Diapos view.
Keeps add slide button visible fixes GH-120
Made strut and overview buttons match component buttons.  GH-118
Added undo support to GH-146
Merge branch 'feature/align-center'
Merge branch 'logo-button-color'
Changed screen cap
Defaults to surface bg if no bg exists fixed GH-149
Softened background colors
Prepends http:// if protocol is missing for a url fixes gh-25
Min height on fileBrowser.  Fixes GH-143
Increments z-index on new component creation.  Fixes GH-153
Only moves etch on mousedown, moves etch faster.  Gh-154
Update links in readme to reflect new resources
Fixed cursor styles that got removed with alignment options
Uploads local images to imgur in order to keep presentations small

This stems from how presentations are sync'ed to RemoteStorage.
We don't want to stick images in as base64 and keep sync'ing those
files across the network.  We're using imgur to host the images
until we can save them directly to the user's remoteStorage.

LocalStorage presents other problems that we need to figure out
how to remedy.
Rolled in an imgup fix
Clears preview while uploading a new image
Made the readme a quicker read
Moved "learn about" before "use" in readme