Update changelog for 1.6.0

CHANGELOG.txt

@@ -1,3 +1,35 @@
+* 1.6.0
+
+- Renderer now lives on its own thread.
+  This is a major architectural change that deserves far more of an
+	explanation than I'm going to provide here.
+
+	I've been wanting to split the renderer onto it's own thread for quite some
+	time, mostly as an academic exercise.
+
+	It turned out to create more maintenance burden than I would have liked,
+	although it does make a few operations easier/cleaner, such as freeing GPU
+	resources from worker threads.
+
+	The API is a message-queue based system for which most of the boilerplate is
+	generated by poof.  There's an `asyncify_render_function` poof routine that
+	takes a function prototype and spits out an `Async` version of the function
+	which pushes a render job onto a work queue.  At this point it's up to the
+	programmer to remember to go actually call the function in the renderer
+	(which is made easier by being reminded of the new, non-enumerated case by the compiler).
+
+- Debug system once again welded directly into the program instead of compiled to a DLL
+	I got tired of maintaining globals in so many places and decided the cost of
+	having the debug system split out into a DLL was not worth the flexibility
+	of being able to load it in other programs.  If I want to use the profiler
+	in other programs, I'll just compile it in.
+
+- Special, compressed vertex data type for world_chunk
+	I wanted to see how much performance I could squeeze out of compressing
+	position and normal data for chunks to 8 bit int from 32 bit float.  Turns
+	out not a massive amount (deferred renderer is mostly texture-bound), but
+	it did shave off a bit.
+
 * 1.5.1
 
 - Fog now driven from C++ (and, by extension, the editor)