improved ROS Support w/keeping stable python support + fixed camera_id bug

[raghavauppuluri13]

• allows package to easily be a ROS package if placed in catkin_ws/src directory. It is also "pip install"-able to ensure backward compatability. this allows easier separation between ROS and python (only rospy dependancy needed to read data)
• Eg:
  • can include node in roslaunch file:

  <node name="left_finger" pkg="gsmini" type="gsmini_node.py" output="screen" >
    <param name="device" value="cuda" />
    <param name="mask_markers" value="true" />
    <param name="calculate_shear" value="true" />
    <param name="calculate_depth" value="true" />
    <param name="camera_name" value="GelSight Mini R0B 28JZ-AU93" /> 
    <param name="show_now" value="false" />
  </node>
  

  NOTE: "GelSight Mini R0B 28JZ-AU93" was gotten from field in front of colon from v4l2-ctl --list-devices
  TODO: better to just fix the camera devices using udev rules. see aloha for an example Done! after doing this, replace the camera_device with the /dev/GELSIGHT_NAME instead after doing the following:

1. Get serial number with: udevadm info --name=/dev/video0 --attribute-walk | grep serial
2. Write udev rules with: sudo vim /etc/udev/rules.d/99-fixed-gelsight-udev.rules

SUBSYSTEM=="video4linux", ATTRS{serial}=="<serial number here>", ATTR{index}=="0", ATTRS{idProduct}=="636d", ATTR{device/latency_timer}="1", SYMLINK+="GELSIGHT_NAME"

3. then, sudo udevadm control --reload && sudo udevadm trigger