Introduce decodeme crate and start supporting old file format versions.

[michaelwoerister]

This PR splits the version-specific parts of file decoding into a separate crate called decodeme. This will make it easy in the future to keep supporting old file formats by making analyzeme depend on multiple versions of decodeme and always have it convert data to the current format.

As an example, this is what the crate graph would look like for analyzeme 17.0.0 if we want it to support a couple of older file formats.

measureme_15_0_0 <--- decodeme_15_0_0 <----+
                                           |
measureme_16_0_0 <--- decodeme_16_0_0 <----+
                                           |
measureme_17_0_0 <--- decodeme_17_0_0 <----+---- analyzeme_17_0_0

See analyzeme/src/file_formats/v7.rs for an example of what it looks like to implement support for an old file format.

Since decodeme does not yet exist for v9.x, this commit will make analyzeme 10.0.0 depend on analyzeme 9.2.0.

TODO:

• Merge Prepare 9.2.0 release #180 and make this PR depend on the 9.2.0 git tag.
• Update installation instructions and CHANGELOG.md
• Add test cases that make sure old fileformats still work? @rylev will take care of this in a separate PR.
• Make error messages suggest to upgrade to a newer version of measureme.

r? @wesleywiser & @rylev

Fixes #178

[rylev]

Looks great!

[michaelwoerister]

I did not update the installation instructions. Instead I opened #182 for discussing a more permanent solution.

Otherwise I think this is ready for a final review.

[rylev]

This looks great!