Add quiet mode
Add quiet mode

Needed to run benchmarks without the stats getting in the way of the benchmark stats.

Fixes #1218

gohugoio/hugo,fedelibre/hugo,mayah/hugo,anthonyfok/hugo,tubo028/hugo,bogem/hugo,mdhender/hugo,fedelibre/hugo,anthonyfok/hugo,bogem/hugo,gohugoio/hugo,fedelibre/hugo,mdhender/hugo,Zenithar/hugo,fedelibre/hugo,digitalcraftsman/hugo,MarkDBlackwell/hugo,digitalcraftsman/hugo,mdhender/hugo,jygastaud/hugo,anthonyfok/hugo,mdhender/hugo,mitchchn/hugo,mitchchn/hugo,MarkDBlackwell/hugo,tubo028/hugo,mayah/hugo,jygastaud/hugo,gohugoio/hugo,Zenithar/hugo