Rename the PKGNAME for the OPSYS-specific user packages to include the OPSYS,
so that they are correctly calculated as independent.

This avoids issues in bulk builds where the package version was taking
precedence and causing the wrong user package to be depended upon.
Note updates to the sysutils/user_* packages.
Bump PKGREVISION of all packages which create users, to pick up change of
sysutils/user_* packages.