Laid out writeBufferToFile utility function
Implement writeBufferToFile utility method
Added -d option string arg in main
Layout of delSingle feature function
Implemented utility function: findTaskInBuffer
Implemented utility function: removeTaskAtIndex
Added delSingleFlag check to errFlag condition for arg parsing in main
Changed writeBufferToFile to allow buffer writing of size 0
Added warning printout if -d task could not be found