fixed some typos in comments
now using relative paths for embedded assets in sample projects

That makes it easier to compile them in other IDEs (like IntelliJ) because it may avoid having to modify the source paths.
added helper script for IntelliJ debugging

The Ruby script provides a workaround for a bug in IntelliJ: it does not copy the specified resources into the output-directory when running/debugging the app in the simulator. Configured as an external tool, the script can do just that.

-> https://youtrack.jetbrains.com/issue/IDEA-94578
added exception for 'starling/build' directory to gitignore file
enhanced handling of pass textures in FragmentFilter (closes #641)
fixed that pivotZ was not used for 'is2D' optimization in Sprite3D
some Sprite3D api reference updates
added project and modules for IntelliJ IDEA
some more places avoiding 'push'
some minor module configuration changes
more IDEA module changes
added unit test module to IDEA project
TextureAtlas now always returns the same SubTexture instances

Since SubTextures are immutable, there's no need to create a new one on each access.
(This has not always been the case.)
AssetManager now processes atlas- and font-XMLs in separate steps

Previously, if you had many/big such XMLs, the final process step could take a while, because all XMLs were processed in one frame. Now, each XML is one "onProgress" call, with one frame inbetween.
small fix in IDEA module
changed module groups in IDEA project
removed 'inline' metadata because it causes a runtime error
added 'soundTransform' property to MovieClip (closes #607)
fixed copy/paste error
removed superfluous colons in asdoc '@param' declarations