Bring back JS precompilation to CC3200

We haven't actually _fixed_ evaluation of precompiled bcode from
non-mmapped memory: we just never free it. For sane use case (do not
evaluate the same file more than once) it should be acceptable.

PUBLISHED_FROM=a9ca2d8fa72e9c40c93415d060ee8db697caa225

docs/c-api/mqtt-broker.h/mg_mqtt_next.md

@@ -7,7 +7,7 @@ signature: |
                                        struct mg_mqtt_session *s);
 ---
 
-Iterate over all mqtt sessions connections. Example:
+Iterates over all MQTT session connections. Example:
 
 ```c
 struct mg_mqtt_session *s;