Mapping: default mapping with dynamic templates can cause them to double on each restart

[kimchy]

[lindstromhenrik]

A consequence of this issue is that it also causes indices to be "refreshed" as the master node sends "double mappings" to its slaves forcing them to refresh the index as the master-mapping does not equal the one that is currently registered on the slaves (as the slave mapping is free of doubles). When using dynamic mappings on clusters with many indices this can cause significant delays when creating new indices.