Created a new abstract iframe component

IFrame component which handles rendering, show/hide, and communication with the iframe

Adapted System Messages Dialog and the Terms Widget to use this new component.
Fixed some issues with setting id attribute.

Commits:

Moving class to iframe namespace

Created abstract IFrame component widget

IFrame panel functionality:
- create iframe
- add HTML to the iframe
- show/hide the iframe
- change the URL of the iframe

IFrame controller
- receives messages from iframes
- each iframe registers, by name
- iframes unregister when removed
- iframe receives a command and value pair

modified DialogBoxWidget to use IFramePanel

updated references to DialogBoxWidget

Separate RPC iframe implementation

Use setAttribute instead of style property

Ignoring GWT compilation folder

Ignoring eclipse settings folder

onMessage now returns a list of Values

added close and okay command strings

updated widgets js command calls

Removed unneeded references

Moved url functionality to RPC dialog box
Merge pull request #3 from Rise-Vision/feature/iframe-component

Created a new abstract iframe component