Merge branch 'develop' of https://github.com/LLNL/spack into features/install_with_phases_rebase

Conflicts:
	lib/spack/spack/build_environment.py
	lib/spack/spack/cmd/install.py
	lib/spack/spack/cmd/setup.py
	lib/spack/spack/package.py
	var/spack/repos/builtin/packages/gmp/package.py
	var/spack/repos/builtin/packages/hdf5/package.py

var/spack/repos/builtin/packages/gmp/package.py

@@ -40,4 +40,9 @@ class Gmp(AutotoolsPackage):
     depends_on('m4', type='build')
 
     def configure_args(self):
-        return ['--enable-cxx']
+        args = ['--enable-cxx']
+         # We need this flag if we want all the following checks to pass.
+        if spec.compiler.name == 'intel':
+            args.append('CXXFLAGS=-no-ftz')
+
+        return args