Also added some references/smart pointers to a couple places
that seemed convenient to the user.
I haven't updated the constructors for RobotDrive() related
examples, pending the results of gerrit change https://usfirst.collab.net/gerrit/#/c/960/
A few things that we are noticing:
--It might be nice if ReturnPIDInput() didn't have to be const;
when people try to override it, they have to remember to put
the const in and if they don't, then the compiler error isn't the
most obvious (especially since this is a change). This would also
apply to PIDGet() in the PIDSource interface.
--SendableChooser still takes raw pointers. This could lead to an
issue I had to debug briefly where you accidentally call
GetSelected() on autoChooser and put the resulting raw pointer
into a unique_ptr, which destroys the pointer when it goes out of
scope. Specifically, I was testing the PacGoat example and
I ended up with a situation where if auto mode was run once, it
was fine, but if it was run twice, the selected command would
have been destroyed by the unique_ptr. I believe that this
just requires updating SendableChosser to take shared_ptr.
--When the samples are compiled with -pedantic, it points out that
START_ROBOT_CLASS macro expansion results in a redundant semicolon.
Change-Id: Ib4c025a61263d0d2780d4253faa31713e15333a5
