Fixed divide-by-zero

Fixed divide-by-zero error when sequences in a file or across all files total zero
Fixes #458
Update readstats.py

styling (chars per line reduce to < 80)
Update ChangeLog
Syntax error
Merge pull request #522 from cowguru2000/patch-1

Patch 1
initial commit of saturate-by-median script
added ChangeLog entry for saturate-by-median; cleaned up script a bit
Merge pull request #531 from ged-lab/feature/saturate_by_median

Added a new sandbox script for saturation analysis of low-coverage data sets
added hackathon foo
hackathon/dev links
initial getting started docs
more updates
more hackathon getting started updates
more docs update
more info
more updates
updated with link to test coverage
make test fails because it can't find `pip2`
Trying it with normal pip
Changed amount of memory needed for test_save_load_merge
guide to testing etc