Merge pull request #1 from talex5/master

Update to Mini-OS 0.2
Update URL of MiniOS in README to v0.2
Merge pull request #2 from avsm/master

Update URL of MiniOS in README to v0.2
This really ought to be a Makefile, but split out fetch/install for easier release packaging
Add a `make release` target
Merge pull request #3 from avsm/master

Release scripts
fix travis
Merge branch 'master' of github.com:mirage/mirage-xen-libs
Travis: fix again
Upgrade to libmini-os 0.3 and openlibm 0.4

Also, don't build in debug mode (this disables all optimisations).