update graphicsExample screenshots to Xcode 4.6.3
of 0.7.4 already has the "MyApps" workspace created for you, update screenshot
since the initial workspace is made for you this screenshot is obsolete
final rename of preRelease to of_v0.7.4_osx_release in the text
more MyFirstWorkspace to MyApps rename
Merge pull request #162 from jedahan/master

More 0.7.4 changes to show how much easier it is to start with oF