fix MXCSR default value

XEN fails to initialise its vcpus to behave like actual cpus. One
instance of this is that the MXCSR is not setup to the default
value documented in as documented in AMD64 Architecture
Programmer's Manual Volume 1: Application Programming, Section
Section 4.3.2
Merge branch 'master' into gsocdrm_alter
nrelease: Switch over to dports for all packages.
nrelease - Set dports default, add dports defaults

* Default DPORTS_PATH to /usr/dports.

* Add dports defaults for the git build to match the git we intend to
  prepackage with the installation.
pkg_radd - update to also handle dports

* Detect that dports has been installed.  dports takes priority over
  pkgsrc in this situation.

* For dports we just 'pkg install ...'.  The script also warns if the
  /usr/local/etc/pkg.conf file has not been installed.
Merge branch 'master' into gsocdrm_merger