Dynamic configs

I added the ability to change some Master parameters dynamically. These parameters include:

1. millisToWaitBeforeDeleting
2. mergeBytesLimit
3. mergeSegmentsLimit
4. maxSegmentsToMove

I added a web console interface as well. As a part of this I imported a package called SlickGrid (that's why it looks like I added so many files)! SlickGrid has an MIT license and it seems fine to use. You can read more here: https://github.com/mleibman/SlickGrid