API problem: increment/decrement with negative numbers #96
Description
Calling increment with a negative value causes riak_dt_emcntr to fail. Unclear which component in the stack should be tweaked, but something should turn that into a decrement.
exception exit: {{function_clause,[{riak_dt_emcntr,op,[{increment,-34},{0,0}],[{file,"src/riak_dt_emcntr.erl"},{line,123}]},{riak_dt_emcntr,update,3,[{file,"src/riak_dt_emcntr.erl"},{line,109}]},{riak_dt_map,apply_ops,4,[{file,"src/riak_dt_map.erl"},{line,333}]},{riak_kv_crdt,update_crdt,3,[{file,"src/riak_kv_crdt.erl"},{line,241}]},{riak_kv_crdt,update,3,[{file,"src/riak_kv_crdt.erl"},{line,61}]},{timer,tc,3,[{file,"timer.erl"},{line,194}]},{riak_kv_vnode,do_crdt_update,3,[{file,"src/riak_kv_vnode.erl"},{line,1407}]},{riak_kv_vnode,prepare_put,3,[{file,"src/riak_kv_vnode.erl"},{line,1337}]}]},[{gen_server,terminate,6,[{file,"gen_server.erl"},{line,744}]},{proc_lib,init_p_do_apply,3,[{file,"proc_lib.erl"},{line,239}]}]}