Bug 10403 Project creation should confirm the bin directory can be scrubbed
When a user creates a new project for an existing directory structure, we should confirm that the output directory can be deleted then rebuilt. Some users are creating projects & pointing the output folder at a bin directory which contains more than just .class files which can be rebuilt from the available .java files.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/BuildPathsBlock.java
CPListElement currElement= (CPListElement)elements.get(i);
			boolean isChecked= fClassPathList.isChecked(currElement);
			if (currElement.getEntryKind() == IClasspathEntry.CPE_SOURCE) {
				if (!isChecked) {
					fClassPathList.setCheckedWithoutUpdate(currElement, true);
				}
			} else {
				currElement.setExported(isChecked);
			}
			entries[i]= currElement.getClasspathEntry();
			entryMissing= entryMissing || currElement.isMissing();			
		}
				
		if (entryMissing) {
			fClassPathStatus.setWarning(NewWizardMessages.getString("BuildPathsBlock.warning.EntryMissing")); 
		}
				
		if (fCurrJProject.hasClasspathCycle(entries)) {
			fClassPathStatus.setWarning(NewWizardMessages.getString("BuildPathsBlock.warning.CycleInClassPath")); 
		}	
	}
	/**
	 * Validates output location & build path.
	 */	
	private void updateBuildPathStatus() {
		fOutputLocationPath= null;
		
		String text= fBuildPathDialogField.getText();
		if ("".equals(text)) { 
			fBuildPathStatus.setError(NewWizardMessages.getString("BuildPathsBlock.error.EnterBuildPath"));