Independent deposit

[ninegua]

The previous design of cycle deposit process was synchronized with other cycle related activities (e.g. canister top-up or other deposits) because we had no easy way of calculating how much cycle was deposited by converting from ICP.

But this has changed with the new CMC canister interface. The method notify_top_up(..) now returns the actual amount of cycles sent to the tipjar canister (after depositing user's ICP). So this means the deposit process can be made independent and it is safe to run concurrently too. As a result the we'll have a more simplified and streamlined process.