add trivial checksum algorithm that reflects file size only

Adds a new checksum algorithm named `File-Size-64` whose hash depends only on the size of the input data. The implementations of `Adler-32` and `CRC-32` also are adjusted; the `common` component unit tests ought still to pass. On start-up the server ensures that this new algorithm is listed in the `checksumalgorithm` table. The purpose of this PR is to enable faster in-place import of large files.

*Update:* Note https://github.com/openmicroscopy/openmicroscopy/pull/2741#issuecomment-48285077 and also note that the commits affecting `Adler-32` and `CRC-32` are reverted.