Drop generic terms from ends of Canonical names

Following up on #2659 and #3175, further steps toward an algorithmic
derivation of Canonical Name from App Name.

Rationale
- encodes the existing practice for the great majority of Casks
- such terms are not helpful in search
- for deeper goals see the PRs referenced above

Enforcing these rules would affect 3 current Casks: `time-tracker-mac.rb`,
`mame-os-x.rb`, `bitcoin-qt.rb`.

Pinging @vitorgalvao; I promised to keep you in the loop on all naming issues.