Add macros for queries and messages.
Each message and query is assigned a different number so that it can be passed easily to the head node.
Add macro for query and msg tags.
Each type of message (query, msg) is assigned a number. They will be used as tags when passing messages so the recipient (master) will know what it is getting.
Add MPI header to the include list.
Add master loop.
Add a function for the master thread to loop in. Also, add a macro for a progress message.
Change MSG_PROGRESS to TAG_DATA.
Changed the message content to a separate tag so that its contents could hold the size of the data to come.