COMP: Suppress quoted var warn under CMake 3.1.0
Policy CMP0054 is not set: Only interpret if() arguments as variables or keywords when unquoted.
Run "cmake --help-policy CMP0054" for policy details.
Quoted variables like "jqPlot_DIR" will no longer be dereferenced when the policy is set to NEW. Since the policy is not set the OLD behavior will be used.