Fix Emscripten build system

Makefile.emscripten

@@ -1,15 +1,21 @@
-CC= python /c/Program\ Files/Emscripten/emscripten/1.7.8/emcc
+CC= emcc
 LAUNCHER= start
 RM=rm -rf
 
 LIBS=
-CFLAGS= -s FULL_ES2=1 -s ASM_JS=1 -O1
-LDFLAGS= --embed-file data
-#LDFLAGS= --preload-file data
+CFLAGS= -s FULL_ES2=1 -s ASM_JS=1 -O1 -Wno-implicit-function-declaration
+#LDFLAGS= --embed-file data
+LDFLAGS= --preload-file data
+
 
 RESULT=game.html
 BUILDDIR=build-emscripten
 
+ifeq ($(target),release)
+	CFLAGS= -s FULL_ES2=1 -s ASM_JS=1 -O2 --llvm-lto 1 -Wno-implicit-function-declaration
+	BUILDDIR=build-emscripten-release
+endif
+
 include Makefile.common