Updated help.py plugin

changed help with no args to display list and info on single line. strip new lines from descriptions to present info in no more than two lines. one for short_desc and one for long_desc if present.

Example: 
![screen shot 2013-05-10 at 3 02 05 pm](https://f.cloud.github.com/assets/1441464/490022/fbfbdc26-b9ad-11e2-9bd8-121d6b9e29ea.png)