* swarm: clean up unused private types and functions
Those that were identified by code inspection tool.
* swarm/storage: move/add Proximity GoDoc from deleted private function
The mentioned proximity() private function was deleted in:
1ca8fc1e6fa0ab4ab1aaca06d6fb32e173cd5f2f
* brokenLimitedReader gives error after half size
* TestRandomBrokenData tests chunker with broken reader
* add blocking quitC (instead of errC) and use errC only for errors
* don't close chunkC in tester Split,
* use quitC to quit chunk storage loop
This change imports the Swarm protocol codebase. Compared to the 'swarm'
branch, a few mostly cosmetic changes had to be made:
* The various redundant log message prefixes are gone.
* All files now have LGPLv3 license headers.
* Minor code changes were needed to please go vet and make the tests
pass on Windows.
* Further changes were required to adapt to the go-ethereum develop
branch and its new Go APIs.
Some code has not (yet) been brought over:
* swarm/cmd/bzzhash: will reappear as cmd/bzzhash later
* swarm/cmd/bzzup.sh: will be reimplemented in cmd/bzzup
* swarm/cmd/makegenesis: will reappear somehow
* swarm/examples/album: will move to a separate repository
* swarm/examples/filemanager: ditto
* swarm/examples/files: will not be merged
* swarm/test/*: will not be merged
* swarm/services/swear: will reappear as contracts/swear when needed
