Fixed problem with two modal windows both trying to stay on top,
which caused flickering and made DrJava unresponsive.
Added revision number and build time to the DrJava survey.
M src/edu/rice/cs/drjava/config/OptionConstants.java
M src/edu/rice/cs/drjava/ui/MainFrame.java
A src/edu/rice/cs/drjava/ui/DetachedFrame.java
D src/edu/rice/cs/drjava/ui/TabbedPanesFrame.java
M src/edu/rice/cs/drjava/ui/DrJavaSurveyPopup.java
M src/edu/rice/cs/drjava/ui/config/ConfigFrame.java
M src/edu/rice/cs/drjava/ui/DrJavaErrorHandler.java