Fix ROS buildfarm error

• revert #27 (#40 )

• add header file and use fputs instaed of fprintf to avoid compile error

  • warning: implicit declaration of function
  • warning: format not a string literal and no format arguments

[sample.launch] args improvement (#38)

• [sample.launch] Choose running RViz or not.
• [sample.launch] pass wrench topic name.

Adding more build-in features by sensor (#39)

• Fix reading problems with A6200 version the reply seems to differ for some reason, however this fix it by cleaning up the socket after sensitivity request and filter request
• Set built-in filter at startup
• Add automatical adjustment of LSB/N
  • generalized "readFromSocket" function
  • flushing socket at beginning (to avoid byte offset)
  • receiving calibration (LSB/N and LSB/Nm) from sensor and multiplying it to data
  • tabs vs. spaces cleanup

Contributors: Isaac I.Y. Saito, Kei Okada, Lorenz Halt