[fix][Python] link name's default value for get* methods.

[130s]

Because get{Current, Reference}{Pose, Position, Rotation, RPY} methods handle the case where lname passed is None in their method's logic, those methods should also allow the case where lname is missing.

Also, this PR extracts common portion of procedure when lname was None for better maintenance.

[k-okada]

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[k-okada]

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[k-okada]

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[k-okada]

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[k-okada]

Did you confirmed if this works with old hrpsys ~= 315.1.x, 315.2.x,
These case should be chanced on Travis but I am not confident on testing all cases. I think better to check manually

[130s]

start-jsk/rtmros_hironx#487 (comment) に書いたように下流 Hironx の暫定クラスへのパッチが 315_1_10 のテストが通っていたので大丈夫ではないかということで同 PR は merge 済です．

がこの PR の Travis が失敗してますね…

[130s]

Travis が失敗してますね…

2回ほど Travis 上の build を見ていますが，どちらも同じ1個の job だけ失敗しているようです．"
TEST_TYPE=work_with_315_1_10 TEST_PACKAGE=hrpsys-ros-bridge"

https://s3.amazonaws.com/archive.travis-ci.org/jobs/213581324/log.txt

+++cat /home/travis/.ros/test_results/hrpsys_ros_bridge/rosunit-hztest_tf.xml /home/travis/.ros/test_results/hrpsys_ros_bridge/rosunit-hztest_tf.xml /home/travis/.ros/test_results/hrpsys_ros_bridge/rosunit-hztest_tf.xml /home/travis/.ros/test_results/hrpsys_ros_bridge/rosunit-hztest_tf.xml /home/travis/.ros/test_results/hrpsys_ros_bridge/rosunit-hztest_tf.xml /home/travis/.ros/test_results/hrpsys_ros_bridge/rosunit-samplerobot.xml
<?xml version="1.0" encoding="utf-8"?>
<testsuite errors="0" failures="1" name="unittest.suite.TestSuite" tests="1" time="5.531">
  <testcase classname="__main__.HzTest" name="test_hz" time="5.5305">
    <failure type="AssertionError">average rate (236.127Hz) exceeded minimum (300.000Hz)
  File "/usr/lib/python2.7/unittest/case.py", line 327, in run
    testMethod()
  File "/opt/ros/hydro/share/rostest/nodes/hztest/hztest", line 115, in test_hz
    self._test_hz(hz, hzerror, topic, test_duration, wait_time)
  File "/opt/ros/hydro/share/rostest/nodes/hztest/hztest", line 185, in _test_hz
    (rate, self.min_rate))
  File "/usr/lib/python2.7/unittest/case.py", line 420, in assertTrue
    raise self.failureException(msg)
    </failure>
  </testcase>
  <system-out><![CDATA[Hz: 500.0
Hz Error: 200.0
Topic: /joint_states
Test Duration: 5.0
Waiting for messages
Starting rate measurement
Done waiting, validating results
]]></system-out>
  <system-err><![CDATA[]]></system-err>
</testsuite>

エラーログ見ても原因が分かりません．

(14番のテストがおとおりずらくないか？ と同じか？と思ったものの，今回しっぱしているのは15番のようなので微妙に違うか．)

[k-okada]

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Test PASSed.

[130s]

Travis も通りました．