make behave much like the history stack of web browsers. The
following files were modifed:
M src/edu/rice/cs/drjava/model/BrowserHistoryManager.java
M src/edu/rice/cs/drjava/model/DummyGlobalModelListener.java
M src/edu/rice/cs/drjava/model/GlobalModelTestCase.java
M src/edu/rice/cs/drjava/model/GlobalModel.java
M src/edu/rice/cs/drjava/model/GlobalEventNotifier.java
M src/edu/rice/cs/drjava/model/FindResult.java
M src/edu/rice/cs/drjava/model/GlobalModelListener.java
M src/edu/rice/cs/drjava/model/DummyGlobalModel.java
M src/edu/rice/cs/drjava/model/AbstractGlobalModel.java
M src/edu/rice/cs/drjava/model/BrowserDocumentRegion.java
M src/edu/rice/cs/drjava/ui/MainFrame.java
M src/edu/rice/cs/drjava/ui/ErrorPanel.java
M src/edu/rice/cs/drjava/ui/predictive/PredictiveInputModel.java
M src/edu/rice/cs/drjava/ui/BrowserHistoryPanel.java
M src/edu/rice/cs/drjava/ui/FindResultsPanel.java
M src/edu/rice/cs/drjava/ui/FindReplacePanel.java
M src/edu/rice/cs/util/text/SwingDocumentInterface.java