Add local scheme for SequenceFile and WritableSequenceFile to enable MemoryTap in Test

In the current test mode, MemoryTap doesn't allow SequenceFile/WritableSequenceFile as input or output. I add a CLTextDelimited scheme for SequenceFile/WritableSequenceFile as their local scheme, so they can be used in the test mode. 

This may not be the best way to do it, but it works. I noticed there's a TODO comment in createTap method which plans to make MemoryTap to drop the scheme parameter which seems to be a cleaner solution, but needs more changes. Any thoughts/comments are very welcome! Thanks!