CA-107919: Reduce memory usage when writing large RRDs.

Previously we temporarily allocated an enormous data structure in
memory with partially applied functions all over the place. Now
we don't.

This commit also adds a couple of test programs and some helper
functions to Rrd (of_file and to_file) and removes some dead code.

Signed-off-by: Jon Ludlam <jonathan.ludlam@eu.citrix.com>
Merge pull request #1 from jonludlam/CA-107919

CA-107919: Reduce memory usage when writing large RRDs.
Add the standard complement of files.

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
Bump version to 0.9.0 for initial release.

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
Merge pull request #2 from djs55/add-standard-files

Add standard files, make initial release