Implemented LocalCacheStore for document version information

Signed-off-by: Seemant Rajvanshi <seemant.rajvanshi@gmail.com>
Converted KeyValueStore to use reactive extension

Signed-off-by: Seemant Rajvanshi <seemant.rajvanshi@gmail.com>
Enabled server gc

Signed-off-by: Seemant Rajvanshi <seemant.rajvanshi@gmail.com>