Added smoothing option

Added option to set smoothing_factor of libjpeg:
If non-zero, the input image is smoothed; the value should be 1 for
minimal smoothing to 100 for maximum smoothing.  The default is zero.
show encode timings
Revert "show encode timings"

This reverts commit 57697029aa659dba943fbb1df5f7652a5a0171a6.
Merge pull request #12 from AlexBerner/feature/moreJpegOptions

Added smoothing libjpeg option