add some vote safety into the votes model and generalize it so it can be used for comments in the future
add some vote safety into the votes model and generalize it so it can be used for comments in the future

treygriffith/pullup,larvalabs/pullup,larvalabs/pullup,josegonzalez/pullup,Zarel/pullup,Zarel/pullup,josegonzalez/pullup,treygriffith/pullup,rickhanlonii/pullup,treygriffith/pullup,gitterHQ/pullup,rickhanlonii/pullup,josegonzalez/pullup,Zarel/pullup,gitterHQ/pullup,rickhanlonii/pullup,gitterHQ/pullup,larvalabs/pullup