add auto offset reset

add kafka.SeekDontCheck (segmentio#295)

* add kafka.SeekDontCheck

* fix logic

* touch less code

* use SeekDontCheck in ReadBatch

* add test

fix record timestamp delta (segmentio#266)

* fix record timestamp delta

* better tests

* fix go vet complains

* truncate timestamp to milliseconds in generated message sequences

Add MaxAttempts to Reader (segmentio#264)

Small fix to Dialer to set the ServerName in tls.Config if it is empt…

…y. (segmentio#152)

Updated discardN to return errShortRead if N bytes not available (seg…

…mentio#143)

Merge pull request segmentio#121 from segmentio/clarify_special_offsets

Use named constants for special offsets

Merge pull request segmentio#106 from segmentio/compression-snappy

Add compression