test compilation and linking with MPFR and GMP
better desc.
Merge pull request #2380 from UnixJunkie/conf-mpfr-only

package to detect presence of the MPFR library
+libres3 v0.3

one of our deps requires >= 4.00.0, so require it here as well for now
Sync latest compiler pull requests
Merge pull request #2382 from bactrian/sync-prs-1406070001

Sync OCaml compiler PRs
Add ppx_deriving.
Merge pull request #2383 from whitequark/ppx_deriving

Add ppx_deriving
+mirage-net-xen.1.1.2
Merge pull request #2384 from avsm/mirage-net-xen-1.1.2

+mirage-net-xen.1.1.2
added
Sync latest compiler pull requests
did a new tag
Update URLs for old versions of @mmottl's packages.
Update maintainer on various packages.
frenetic.3.1.0
ox.1.1.0 dependency update
ox.1.1.1
Sync latest compiler pull requests
Merge pull request #2389 from yallop/mmottl-updates

Updates to various @mmottl packages