-e: build size increased considerably for user project going from 5.3 to 5.4

-repro:
--open case_815795-Stripped.zip project (attached in edit) in 5.3
--build standalone and WebGL build
--open same project in 5.4
--build standalone and WebGL build
--NOTICE build size increases
--standalone: 34MB -> 59MB (majority in Data\Resources\unity_builtin_extra)
--WebGL: 3.5MB -> 17MB (in data file)

-forum: http://forum.unity3d.com/threads/webgl-build-size.416219/