Disable strict aliasing

This is motivated by issue #60 to see if we can get away with `-O3`
while still handling the cast of a `Decoder**` to `void**`.

Fixes #60

rebar.config

@@ -7,7 +7,7 @@
 ]}.
 
 {port_env, [
-    {".*", "CFLAGS", "$CFLAGS -g -Wall -Werror -O3"},
+    {".*", "CFLAGS", "$CFLAGS -g -Wall -Werror -O3 -fno-strict-aliasing"},
     {".*", "CXXFLAGS", "$CXXFLAGS -g -Wall -Werror -O3"},
 
     {"(linux|solaris|freebsd|netbsd|openbsd|dragonfly|darwin)",