First patch having the partial implementation of buffer cache
Will be adding more scenarios, but this will provide atleast
a partial view of the implementation, suitable for comments

Added new/few comments, to functions and variables
Removing the unwanted object file

Signed-off-by: Satheesaran <satheesaran@gmail.com>
Created a complete operation of allocating the buffer for the
required block. But there is bug while asking for the same buffer
again, once its allocated.

Next commit will contain a fix for it

To be Implemented still :
1. Releasing the buffer
2. Completing Async Write to disks from buffers, removing
delayed-write flag  and releasing the buffer to free pool
3. Other fixes and comments

Signed-off-by: Satheesaran <satheesaran@gmail.com>