Behavior Tree Editor internals rework - ALPHA!

Pretty please - do not use this version for packs until proven stable

In this version I've reworked internals of BehaviorTree editor. Long-term, this will allow to do many optimizations in how quickly BTs are loaded/rendered/etc. Short-term it may lead to a whole bunch of different bugs and problems which I will be closely monitoring and working on asap. In that regard, please, do not use this version to publish packs of auras, use it by yourself - that way in case something will explode - like some random BT will vanish - this won't have avalanche effect and will affect only few users. Alphas are intended to be used for testing-purposes only.

Things that should be noticeable - larger (50+ nodes) trees should load a bit quicker (10-20%) and, most importantly, the bug, which made nodes dissapear when quickly switched between multiple large BTs, should be fixed. This was the driver behind this rework and the new approach should protect from similar problems in the future.

Bugfixes/Improvements

• [Capture] Fixed crash which occurred if FramesPerSecond value was set to something very small like 1e-10
• [UI] Fixed crash which happened when Offset Width + Position/ContentAnchor were set in Overlays
• [Scripting] Fixed a problem in error highlighting in the text editor - now it should properly underline erroneous lines as it was pre-Razor changes
• [Web] Changed "Download pack" to "Download portable pack" - hopefully this will make more users click on that button rather than downloading the program + importing manually