Remove GetValue call from IJKIndex and use implict cast instead.

This removes a whole chunk of conditional code.
Remove unused elements in test files.

They were causing errors about unused things in clang.
Merge branch 'FixWarnings'
Initialize values in pair test.

Using uninitialized values was causing a failure in the test when
compiled with optimizations on.  The optimization probably skipped some
operations on the uninititalized values.
Merge branch 'FixPairTest'
Merge branch 'simplify_arg_binding'
Merge branch 'tidy_internal_functor_impl'
Add in a XeonPhi Toolchain file for cross compilation.
Add FindBoostHeaders which is a simplified version of FindBoost.

We simplify the boost header searching and remove all the complexity
of looking for boost libraries.
Update UseDax* to use FindBoostHeaders module.
Update Dax to use FindBoostHeaders.cmake instead of CMake FindBoost.cmake
Update Dax install rules to install all cmake modules we have.
Make sure we install the xeon phi toolchain file.
Merge branch 'xeonphi_toolchain'
Merge branch 'find_boot_headers_only'
Add missing closing ).
Merge branch 'xeonphi_toolchain'
Add missing Copyright statement to XeonPhiToolchain.
Merge branch 'xeonphi_toolchain'
dax::Extent now is properly aligned based on id size.

Previously we aligned dax::Extent based on scalar size which was wrong, since
it only contains dax::Ids.