Added: if file doesn't exist when doing a write
Merge branch 'master' of https://github.com/sysc-3303-1000000/TFTP
Added: Cleaned up the entirety of the Client, added comments where
required. Removed some redundancy. Added new functionality to the client
UI (Iteration 5 not yet implemented). User is now able to select what
they wish to save the file on the server as, and also select what they
wish to save it as on their side.