* [NOD-256] Add error log
* [NOD-256] Add error log
* [NOD-256] Fix typo and comment
* [NOD-256] Remove btclog dir
* [NOD-256] Format project
* [NOD-256] Add error log files
* [NOD-256] Add an option to add a log file to write into to an existing backend logger
* [NOD-256] Get rid of redundant logs initialization
* [NOD-256] rename initLogRotators to initLog
* [NOD-256] Get rid ExampleSignTxOutput and convert ExampleBlockDAG_ProcessBlock to a regular test
* [NOD-256] Show error message if os.Exiting from initLog
