Delta multiplier added to Editor Properties.
New emitters are configured as bare-boned skeletons.

Initial emitter remains the same however.
Add ScreenAdapter.java for GWT
Create ScreenAdapter.java
Update NetJavaImpl.java

issue 1576
Kotlin compatibility fix
Update Net.java
Update IOSNet.java
Updated maven-download-plugin version to 1.1.0
Merge pull request #518 from nikitatikh/proxy-fix

Updated maven-download-plugin version to 1.1.0
Merge pull request #513 from fogone/master

Kotlin compatibility fix
Added Rectangle functionality

Added the ability to calculate the aspect ratio and center position, as
well as centering to a point, and fitting inside/outside another
rectangle
Change IntSetIterator to public

Fixes Issue 1592.
Throw exception when no valid assetpath is defined

Fixes Issue 1579.
Add exclusion for voxel example
calculate -> get and returns
Forgot to change centerTo->setCenter and more chains
Don't allow null selected nodes.
AssetLoader changed to receive the resolved FileHandle along with the file name.

See comments in #517.
Sync GWT emulation with changes in f3b2d34