adding joint trajectory controllers

spider_control/CMakeLists.txt

spider_control/config/spider_control.yaml

spider_control/control.py

spider_control/launch/spider_control.launch

spider_control/package.xml

spider_description/urdf/spider.gazebo

spider_description/urdf/spider.xacro

spider_gazebo/worlds/30.1.1.1282760.dem

spider_gazebo/worlds/a

spider_gazebo/worlds/an

spider_gazebo/worlds/an.aux.xml

spider_gazebo/worlds/ant

spider_gazebo/worlds/antarctica

...1000x1000/materials/textures/AS16-110-18026HR-512x512.jpg

...textures/NAC_DTM_APOLLO15_E261N0036_257x257+7472+2152.png

...zebo/worlds/apollo15_landing_site_1000x1000/model-1_4.sdf

...azebo/worlds/apollo15_landing_site_1000x1000/model.config

...r_gazebo/worlds/apollo15_landing_site_1000x1000/model.sdf

...r_gazebo/worlds/cinderblock2/meshes/cinder_block_wide.dae

spider_gazebo/worlds/cinderblock2/model.config