Move the default location of the data directory in the tar/zip installs out of the install directory

The Nexus installation is temporary, once you upgrade it becomes obsolete. The data directory is permanent, it needs to be preserved across all upgrades. The default data folder should be "../sonatype-work/nexus3/data"

We learned the hard way a very long time ago that it is a therefore good idea to have the default location of the data directory be outside of the installation directory (under "../sonatype-work/"). Doing this will prevent two common errors:

1. Users unpacking new installations directly on top of existing installations
2. Users mistakenly deleting or damaging work directories when they try to move them out of old installations.

An empty sonatype-work/nexus3 folder needs to be included in the bundle so the resulting folders have the correct permissions

We must call out in the release notes and upgrade notes that the data folder has been moved. At this time, we expect the move to be done one time manually by the end users, this is not being automated.

Users upgrading from pre-3.1 will need to either:

• manually move (recommended) or symlink the data folder to expose it to where pre-3.1 stored it
• configure Nexus 3.1 to point to the existing data folder inside the pre-3.1 layout (not recommended)

*Users:* Please consult the official upgrade documentation for upgrade instructions pertaining to this move