add clearJointAngles and clearJointAnglesOfGroup()

[k-okada]

this clears all input queue by setJointAngles, setJointAnglesOfGroup, setJointAnglesSequence and setJointAnglesSequenceOfGroup()

[k-okada]

Refer to this link for build results (access rights to CI server needed):
http://jenkins.jsk.imi.i.u-tokyo.ac.jp:8080/job/hrpsys-qnx/2102/

Build Log
last 10 lines

[...truncated 6017 lines...]
    at org.jenkinsci.plugins.ghprb.GhprbRepository.createCommitStatus(GhprbRepository.java:122)
    at org.jenkinsci.plugins.ghprb.GhprbBuilds.onCompleted(GhprbBuilds.java:118)
    at org.jenkinsci.plugins.ghprb.GhprbBuildListener.onCompleted(GhprbBuildListener.java:27)
    at org.jenkinsci.plugins.ghprb.GhprbBuildListener.onCompleted(GhprbBuildListener.java:12)
    at hudson.model.listeners.RunListener.fireCompleted(RunListener.java:199)
    at hudson.model.Run.execute(Run.java:1786)
    at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:43)
    at hudson.model.ResourceController.execute(ResourceController.java:98)
    at hudson.model.Executor.run(Executor.java:374)

Test FAILed.