Download squirrelsql-version-plugin JAR file with all dependencies

This project produces a maven mojo that can set the System property "squirrelsql.version" so that it can be used globally by the installers and the update-site projects. It accepts the project version as an argument which it uses to decide what the squirrelsql.version should be. If the project version ends with "-SNAPSHOT", then the squirrelsql.version will be set to Snapshot-{timestamp} where {timestamp} is the current timestamp in the form of YYYYMMDD_HHMM. If however, the project version does not end with "-SNAPSHOT", then squirrelsql.version will be set to the value of the project version.