CLJCLR-8: Enhance compiler support for loading namespace from .NET assemblies
Fix version on add-ns-load-mapping and add comment to RT.DisableFileLoad
Convert assembly load methods to exceptions versus status return
Merge branch 'master' of https://github.com/clojure/clojure-clr

Conflicts:
	Clojure/Clojure.Source/clojure/core_clr.clj
	Clojure/Clojure/CljCompiler/Compiler.cs
	Clojure/Clojure/Lib/RT.cs