Fixed|Debian: Package build rules (linker path)

libassimp is built in a nonstandard location (under external).

distrib/debian/rules

@@ -1,13 +1,13 @@
 #!/usr/bin/make -f
 APPNAME := doomsday
+ASSIMP_DIR := $(shell if [ -e ../doomsday/external/assimp ]; then echo ../doomsday/external/assimp; \
+                else echo doomsday/external/assimp; fi)
+
 builddir:
 	mkdir -p builddir
 
 builddir/Makefile: builddir
-	if [ -e ../doomsday/external/assimp ]; \
-		then cd ../doomsday/external/assimp; \
-		else cd doomsday/external/assimp; fi; \
-		cmake -G "Unix Makefiles" && make -j2
+	cd $(ASSIMP_DIR) && cmake -G "Unix Makefiles" && make -j2
 	cd builddir && qmake-qt4 PREFIX=/usr CONFIG+=deng_fluidsynth \
 		CONFIG+=deng_extassimp CONFIG+=release \
 		DENG_BUILD=`../build_number.py --print` \
@@ -20,7 +20,7 @@ build-indep: build-stamp
 build-stamp: builddir/Makefile
 	dh_testdir
 	# Add here commands to compile the package.
-	cd builddir && $(MAKE)
+	cd builddir && LD_LIBRARY_PATH=`pwd`/../$(ASSIMP_DIR)/lib $(MAKE)
 	touch $@
 
 clean: