[PREVIEW]- fluency 2.4; - port to gradle

[VitaliyKulikov]

• testing in progress
• need runtime lookup for Static Fields, aka ${ctx:userId}
• seems, new Fluency has few more configuration settings (ex.: jvmHeapBufferMode)
  (need investigation)

    private Long maxBufferSize;
    private Integer bufferChunkInitialSize;
    private Integer bufferChunkRetentionSize;
    private Integer bufferChunkRetentionTimeMillis;
    private Integer flushAttemptIntervalMillis;
    private String fileBackupDir;
    private Integer waitUntilBufferFlushed;
    private Integer waitUntilFlusherTerminated;
    private Boolean jvmHeapBufferMode;
    private ErrorHandler errorHandler;