Add cachedpage.sh to identify potential caching problems

Running:
./scripts/cachedpage.sh 5413e645da2067687627b9a9c6a1aee914328a63
Produces cached.html and cached_special.html

Added useformat=mobile, otherwise desktop pages are saved (jgonera)

Change-Id: Ifb84b8cd2b46f9e92053de12c6ee4749c9814be2
Merge "Add cachedpage.sh to identify potential caching problems"