README improvements: formatting and usage notes.
Merge pull request #17 from copious/master

README improvements: formatting and usage notes
Merge pull request #1 from colinmollenhour/master

Merge pull request #17 from copious/master
Merge branch 'master' into feature/instrumentation

Conflicts:
	README.md
Removing unnecessary class_exists checks.
Merge branch 'feature/instrumentation' into feature/configurable-sleeps