getFloat() seems to have an issue with reading modified values and always
returns the default value instead. This needs further investigating, but
for now making it use getDouble() internally appears to resolve the issue.
This attempts to revert cannoning mechanics to pre-1.8 behavior. A huge
thanks to TheIceAP who championed almost every fix in this patch.
Another shoutout to Jebediah Smith from SportBukkit for the velocity
update patch which mostly fixes the client issue of TNT moving in water.
Allows us much greater control over the Spigot portion of the code
and makes us more "proper"
Credit to @Dmck2b for originally passing the idea along a while back