Upgrade to antlr v4.5
Upgrade to antlr v4.5

Pick up the fix to antlr/antlr4#487 to eliminate spurious annotation
processor warnings.

Fixes #185

caxqueiroz/ethereumj,loxal/ethereumj,gerbrand/ethereumj,loxal/FreeEthereum,loxal/FreeEthereum,vaporry/ethereumj,chengtalent/ethereumj,BlockchainSociety/ethereumj-android,ddworken/ethereumj,fjl/ethereumj,swaldman/ethereumj,shahankhatch/ethereumj,loxal/FreeEthereum,swaldman/ethereumj,syng-io/ethereumj-android