Known limitations:
- comment for now testisofs, as iso9660fs is known to be broken.
Benefits:
- near 3x speed improvement on C++ code compilation, bringing down
make build to from 44min down to 21min.
- Allows for X applications to work properly, which should be available
in near-term future through pkgsrc for 3.3.0.
Change-Id: I8f4179a7ea925ed381642add32cfd8c5822217e4
31b808b8fa