Flux package reworked to include all new dependencies, fixed issues with a
clean-build of hwloc, lua and czmq as well that prevented flux from building
cold on a minimal system.

- _cross_provider_maps() had suffered some bit rot (map returned was
  ill-formed but still worked for cases with one vdep)

- ProviderIndex.satisfies() was only checking whether the result map
  was non-empty.  It should check whether all common vdeps are *in*
  the result map, as that indicates there is *some* way to satisfy
  *all* of them.  We were checking whether there was some way to
  satisfy *any one* of them, which is wrong.

- Above would cause a problem when there is more than one vdep provider.

- Added test that covers this case.

- Added `constrained()` method to Spec. Analogous to `normalized()`:
  `constrain():constrained() :: normalize():normalized()`

Fixed Mitos dependency and added new version

Revert "WIP: openssl: set KERNEL_BITS to make ./config work"

- Can't think of a better way to do this.
- The externals integration will cause spack to die in weird ways for
  users who just pull from develop.

cleaning up commits for merge request

WIP: openssl: set KERNEL_BITS to make ./config work

python: target OS X 10.6

dbus: disable launchd support

Libxml2 drop python dep

Paraview update deps

Matplotlib optional deps

Add CleverLeaf package

packages/mvapich2 : added support for process managers and network types

Added Python Twisted library

Fixed -l flag for 'spack extensions'

Update PAPI

Don't use https for downloading

add judy dynamic array/meta-trie/hash table lib

modified warning to reference spack clean

Add damselfly package

Just adding judy.

clean --dist has been removed, command fixed to something that works.

Targeting anything older lacks rpath stuff which configure uses.

Why OpenSSL refuses to build without this (it explicitly warns about it)
is a mystery.