Appropriate message handling in deleteMsg

-Fixed deleteMsg (was returning the next user form the list for some
reason)
-Changed the variable’s name “head” to “usr”, since we’re merely giving
it a specific User node as argument
-Corrected cmpItems prototype
deleteStuff.c, instead of just deleteMsg.c
Malloc the size of a Message for topMsgs

Herp derp
Better item management

-Added findItem the returns the User that has the given Message
-Better item handling in cmpItems
-Added respective prototypes
-“Aired” the code with spacing