builder/vmware: Add support for Workstation 9 (Linux).

Now the VMware builder should automatically pick between Fusion 5 and
Workstation 9, based on which one is installed.
builder/vmware: split drivers out into individual files
builder/vmware: wording
Update CHANGELOG
scripts: Use XC_ARCH/XC_OS to limit what arch/os combo is built
builder/vmware: workstation 9 show stderr if command fails
builder/vmware: look for license for WS9