Added daily maintenance thread execution and refactored existing
maintenance action code

Change-Id: I67e368f2c1a11e6bb7f9cf46cee23c9bf110d496
Corrected Singleton implementation of MBank and added maintenance launch
functionality, refactored maintenance thread 
Change-Id: Ifa153668abe0cb50af548d224f536036bd9d2c8b
Added toString() for Client and Deposit classes
Added ViewClientDetails() action

Change-Id: I3951d2629d47a2cd4034e64535fd0cdbd4b612cc