Parameters: Help display w/ description, units, valid range & accepted values where available

Parameter help:
- touch any row on the parameters screen, parameter documentation will be displayed if available. 
* Content is from ParameterMetadata.xml
![screenshot_2013-10-14-03-05-59](https://f.cloud.github.com/assets/4014433/1323924/8cd864b4-349f-11e3-9bf9-03bc4cd2136a.png)

![screenshot_2013-10-14-02-04-58](https://f.cloud.github.com/assets/4014433/1323903/4520d06c-349e-11e3-9257-ebe180c91107.png)