APEX Lifecycle Management

Hello. I have a question about lifecycle management for team development.  We are running into maintenance difficulties/hinderences as parts of the team work on different versions of the application at the same time (e.g. some developers are fixing issues while the rest of the team is already working on the next release).  How do you handle the typical parallel development scenario?

It would be ideal to be able to merge changes similar to traditional code.  As of right now, all merges are manual--that is if a new page is creates, we can copy the page into the other application otherwise we have to manually make all the changes to the other versions.  I've looked into the APEXExport and APEXExportSplitter command line tools, but merges were still manual procedures.  I've read that some suggestions about making each capability (or group of screens) a different application.  So the "application" would be use multiple APEX applications.  That would allow "merging" a much smaller application.