am d989a8e3: Added check for the version of Gnuplot.

Merge commit 'd989a8e37771a2f97b1c6ec45f29bb1bc94e7299' into eclair-plus-aosp

* commit 'd989a8e37771a2f97b1c6ec45f29bb1bc94e7299':
  Added check for the version of Gnuplot.