Allow ignoring irrelevant parts of the version string in "latest" semver calculation

[vyadh]

The plugin currently uses semver to calculate what is the latest build, and either highlights/fades out deployments.

However, if you're not using the exact version number through different environments, the plugin does not highlight deployments as expected. For example, if you leave the build numbers for each deployment as independently incrementing.

A simple way to solve this is to assume that the semver part comes first, and anything after is just metadata. We could do this by ignoring anything after a space in the version string.

We should also better document how this works in the readme.