v2.9.0 New release tag to match version number in library.properties.

This 2.9.0 release tag is created so that the version number of the tag and the library version number in the library.properties file are the same.

v0.9.0 Minor updates for release via Arduino library manager.

Minor tweaks to facilitate release via Arduino library manager. Concurrent with v0.9.0 Luni and LuniJS releases.

Simulataneous release with version 0.8 of Luni library.

This release will be the change source for the pull request to implement the device driver extension, unless patch releases are needed first.

Snapshot before register-read-write slash and burn.

Matches the device-driver.md document v0.2.