dbg_profiler.lua: since gadget ChatAction no longer called twice, re-added the following
* "/luarules profile" toggle SYNCED (can show/hide)
* "/luarules uprofile" toggle UNSYNCED
* "/luarules fprofile" toggle <5% filter
* "/luarules profilegadget <gadgetName> <second>" sum SYNCED usage for a gadget for set second (also a toggle)

This is for profiling gadget's cost.
Merge pull request #42 from xponen/dbg_profile

dbg_profiler.lua: re-added some profiler command that was reverted due to bug (fixed)