comment update; change default C for calc-error-profile
added scripts/sample-reads-randomly.py, an implementation of reservoir sampling
Merge branch 'reservoir_sampling' into kmer_error_profile
Merge pull request #191 from ged-lab/reservoir_sampling

A simple implementation of reservoir sampling for shotgun sequencing.
Merge branch 'master' of github.com:ged-lab/khmer into kmer_error_profile
cleanup of calc-error-profile