Try to avoid searching for dependencies twice
Try to avoid searching for dependencies twice

Refactor lcm_option to require its dependency immediately if the option
is ON (e.g. a second run after the user has used ccmake or cmake-gui),
and to not search again if the dependency is already found.

bluesquall/lcm,bluesquall/lcm,adeschamps/lcm,adeschamps/lcm,adeschamps/lcm,adeschamps/lcm,bluesquall/lcm,lcm-proj/lcm,bluesquall/lcm,bluesquall/lcm,adeschamps/lcm,lcm-proj/lcm,lcm-proj/lcm,bluesquall/lcm,bluesquall/lcm,lcm-proj/lcm,lcm-proj/lcm,lcm-proj/lcm,lcm-proj/lcm,lcm-proj/lcm,adeschamps/lcm,adeschamps/lcm,adeschamps/lcm