Create passwd.md

Added a few exemples, and basic description of passwd
Update passwd.md

Added info about the {{options}} flag, as requested.
Clarify OS support
Add David badges
Merge pull request #117 from ZDroid/david-badge

Add David badges
README remove Bitdeli + add Travis + NPM

BitDeli wasn't working + now superseded by Github Analytics
https://github.com/blog/1672-introducing-github-traffic-analytics
add ss.md
Create CONTRIBUTING.md
CONTRIBUTING: fix footnote
README point to new CONTRIBUTING page
Add man
Added man.md. Fixes #121
Move pgrep to common instead of only OS X
Adds missing quote to say command
Merge pull request #124 from jeroenj/patch-1

Adds missing quote to say command
Merge pull request #123 from Tenzer/pgrep-move-to-common

Move pgrep to common instead of only OS X
Merge pull request #122 from notpeter/master

Fixes #121 Added man
Merge pull request #101 from 007N/patch-2

Create passwd.md
ss: refine examples
passwd: cleanup style to be similar to other pages