Refcount GPIB error checking so we can minimize redundant checks

Also, make dummy test instantiate a cell emulator
Reduce some kludge timers

TEST=cellular_*
BUG=chromium-os:24234

Change-Id: I2362ed520dc66ddafbdd2c43723e421717cc5160
Reviewed-on: https://gerrit.chromium.org/gerrit/12925
Reviewed-by: ttuttle <ttuttle@chromium.org>
Reviewed-by: Jason Glasgow <jglasgow@chromium.org>
Commit-Ready: David Rochberg <rochberg@chromium.org>
Tested-by: David Rochberg <rochberg@chromium.org>
6 files changed