[HatoholArmPluginGate] Use a custome GLib's context if specified.
[HatoholArmPluginGate] Run the timer on the specified GMainContext.

The pipe and the timer should use the same context to avoid a race.
[HatoholArmPluginTestPair] Move HatoholArmPluginTestPair to HatoholArmPluginTestPairArg.

This enables a user of HatoholArmPluginTestPair to specify arguments for
HatoholArmPluginGateTest directly.
[HatoholArmPluginGate] Remove an unexpired timer properly.

The previous code cannot remove a timer if it's attached
to non-default context.
[Helpers] Add a new helper class: GLibMainLoop.
[HapProcessStandard] Fix the problem in which the AMQP receiver thread is blocked.

This commit includes the test that causes a deadlock when the previous code
is used. The condition is that an ArmPlugin receives reqFetchItems() while acquireData()
is executing.
[server][test][Helper] Fix indent
Merge pull request #698 from project-hatohol/fix-block-aquire-data-by-req-fetch-item-4

Fix block aquire data by req fetch item 4