FIX: patch RemoteDebugger.start and allow RemoteDebugger connections by default

In the new b2g-desktop shell.js debugger server is now started
by RemoteDebugger.start, so we need to change patch-start-debugger
accordingly.

To prevents user confirmation on simulator connection to the RemoteDebugger,
we needs to redefine RemoteDebugger.prompt.
update B2G to 2013-01-18
update Gaia to tip of v1-train branch
Merge pull request #259 from mykmelez/update-b2g-gaia

update B2G/Gaia to 2013-01-18 (Firefox OS 1.0 branches)