Remove meta information from host allocator policy

Remove meta information from host allocator policy

Also prevent HostAllocator to be copied/propagated.
A HostVector shouldn't be copied without the calling code
having a choice on the pinning policy.
This commit prevents copy construction. Move construction and
copy and move assignment is still allowed.
For move/swap nothing is changed.
For copy assignment the pinning policy of the destination
container is used.

Fixes #2612

Change-Id: I15034e4db2434ea46eda84e70e3f8e6072660d20