Added getter methods for padding and margin attributes in Element
Bugfix: Element.findElementById() didn't use the to find element id passed as parameter, but local field which causes every find to return 'this'
Renamed method Screen.findElementByName() to findElementById() according to Element.findElementById(); old method is still available but @Deprecated
Merge pull request #89 from floyd1982/1.4

1.4 Pull request: bugfix, getters for padding and margin fixes #85