* [NOD-641] Upgrade to github.com/pkg/errors v0.9.1 and use errors.As where needed
* [NOD-641] Fix find and replace error
* [NOD-641] Use errors.As for error type checking
* [NOD-641] Fix errors.As for pointer types
* [NOD-641] Use errors.As where needed
* [NOD-641] Rename rErr->ruleErr
* [NOD-641] Rename derr->dbErr
* [NOD-641] e->flagsErr where necessary
* [NOD-641] change jerr to more appropriate name
* [NOD-641] Rename cerr->bdRuleErr
* [NOD-641] Rename serr->scriptErr
* [NOD-641] Use errors.Is instead of testutil.AreErrorsEqual in TestNewHashFromStr
* [NOD-641] Rename bdRuleErr->dagRuleErr
* [NOD-641] Rename mErr->msgErr
* [NOD-641] Rename dErr->deserializeErr
* [NOD-275] Moved getBlockTemplate and related functionality to a separate file.
* [NOD-275] Started moving handlers to separate files.
* [NOD-275] Fixed merge errors.
* [NOD-275] Moved all handlers out of rpcserver.go.
* [NOD-275] Moved non-shared functions out of rpcserver.go.
* [NOD-275] Moved handleGetAllManualNodesInfo to a separate file.
* [NOD-275] Moved handlers out of rpcwebsocket.go to separate files.
* [NOD-275] Fixed import error.
* [NOD-275] Renamed all handler files to include underscores.
* [NOD-275] Moved common rpc helper functions to common.go.