Bug 972265: Maintain connect delay in UnixSocketConsumer, r=kyle

UnixSocketConsumer now maintains a delay for re-establishing closed
connection. The initial delay is zero, so that the first connect call
is processed immediately. At the first failed attempt to connect, the
delay is set to ~1 second, and is increased by a factor of 2 on each
successive error until it reaches ~1 minute.

The UnixSocketConsumer code resets the delay to zero if it is lower
than the time that the connection was open. This heuristics protects
against cases where the peer establishes a connection, and closes it
shortly afterwards. Incompatible versions of rild show this behavior.
Bug 972265: Use connect delay in RIL IPC code, r=vyang

When trying to re-connect a socket, the RIL IPC code now respects
the delay that is suggested by the UnixSocketConsumer.
Bug 972265: Use connect delay in NFC IPC code, r=allstars.chh

When trying to re-connect a socket, the NFC IPC code now respects
the delay that is suggested by the UnixSocketConsumer.