Fix sorting of vj in route schedules

We were only comparing vj with their first stop_time defined. So with this case:

A    7h0
B    8h0   7h30      
C             8h00

And we actually want: 
A             7h00
B   7h30  8h00
C   8h00
there is a missing space there (and while you're on it, you can const& the string (and use boost::find_if :) )