Remove scanjob.go. Refactor operation.go a bit.

Change-Id: Id66d275df3829baa57e9b958feae6a12097b3760
Refactor operations.go.

Change-Id: I49cfa1bcddb20fb70180648d4d9a69181db120aa
Refactor freelist get for operations.

Change-Id: I78a3dc8f844a116667354284c56e66ca5f158916
Some more minor refactorings in operation.go.

Change-Id: I032b976e0880151c3f3fdb3234fb65e484f0e2e5