Cleanup of header install for plants/CMakeLists.txt
Cleanup of header install for plants/CMakeLists.txt

 * Multiple header files were listed twice
 * Moved header file install directive to near where the corresponding
   binary was built

sheim/drake,sheim/drake,billhoffman/drake,billhoffman/drake,billhoffman/drake,sheim/drake,sheim/drake,billhoffman/drake,billhoffman/drake,sheim/drake,billhoffman/drake,billhoffman/drake,sheim/drake,billhoffman/drake,sheim/drake,sheim/drake