apps: refactor reader command line options

this removes the individual reader command line flags in favor
of a single --reader-opt flag (that can be specified multiple times)
and passes through the value to nsq.Reader using the new reader.Configure().

nsq_to_file:
    * deprecated --gzip-compression in favor of --gzip-level
    * deprecated --verbose in favor of --reader-opt=verbose

nsq_to_http:
    * deprecated --throttle-fraction in favor of --sample
    * deprecated --http-timeout-ms in favor of --http-timeout (which is a
      duration flag)
    * deprecated --verbose in favor of --reader-opt=verbose
    * deprecated --max-backoff-duration in favor of
      --reader-opt=max_backoff_duration=X

nsq_to_nsq:
    * deprecated --verbose in favor of --reader-opt=verbose
    * deprecated --max-backoff-duration in favor of
      --reader-opt=max_backoff_duration=X
bump Godeps for go-nsq to v0.3.4
add go1.2 to travis