Split up build so dependencies can be cached.

However not sure if this is ideal from a security perspective.

Dockerfile

@@ -2,11 +2,6 @@
 FROM	alpine:latest
 LABEL	authors	"Isaac \"Ike\" Arias <[email protected]>,James Stone"
 
-ENV	BLENDER_MAJOR	2.77
-ENV	BLENDER_VERSION	2.77a
-ENV	BLENDER_BZ2_URL	http://mirror.cs.umn.edu/blender.org/release/Blender$BLENDER_MAJOR/blender-$BLENDER_VERSION-linux-glibc211-x86_64.tar.bz2
-
-
 RUN	apk add --no-cache \
 	--update \
 	curl \
@@ -15,12 +10,18 @@ RUN	apk add --no-cache \
 	freetype \
 	mesa-dev \
 	mesa \
-	libxi \
-	&& mkdir /usr/local/blender \
+	libxi
+
+ENV	BLENDER_MAJOR	2.77
+ENV	BLENDER_VERSION	2.77a
+ENV	BLENDER_BZ2_URL	http://mirror.cs.umn.edu/blender.org/release/Blender$BLENDER_MAJOR/blender-$BLENDER_VERSION-linux-glibc211-x86_64.tar.bz2
+
+RUN	mkdir /usr/local/blender \
 	&& curl -SL "$BLENDER_BZ2_URL" -o blender.tar.bz2 \
 	&& tar -jxvf blender.tar.bz2 -C /usr/local/blender --strip-components=1 \
 	&& rm blender.tar.bz2 \
 	&& apk del curl
 
+
 VOLUME	/media
 ENTRYPOINT	["/usr/local/blender/blender","-b"]