New Skin icons and styles.
Adds LoadingBar widget and test.
Removes unused DownloadFileListener.
Changes DownloadFileWorker to return the completion as result.
Now it can be cancelled in the middle of the download.
Changed WorkerExecutor to allow multiple workers
of the same class working in parallel.

Fixed a bug where the CANCEL event wouldn't get fired because the worker was removed
from the map too early when results were launched on UI thread.
Adds DownloadManager.
Adds RepoTile to SearchGallery.
Improves SearchRepoViewTest.
"Mokaps" categories added for the repo, so we can store full projects
Moved BaseTweenDropdown and EnterAnimationEditor classes
Added method to lock only the context pane and minor bug fixed
Moved the fx widgets and views to interaction context pane.
Removed the mode menu and added button to open the interactiveContextPane
Merge pull request #917 from jtorrente/repocategorygame

"Mokaps" categories added for the repo, so we can store full projects
Added play button.
Added close button to hide context pane and minor improvement in "full view"
Merge pull request #918 from gorco/fxinteraction

Fx-interaction merged
Improves LoadingBar height, adds DelayedRemovalArray to WorkerExecutor and fixes CopyEntityResources worker.
Fixed minor bug
Added skin