Allow full debug symbols for MSVC release builds
Completing #842
Fixed #841: Add possibility to broadcast an index with hpx::lcos::broadcast
Fixed #827: Enable MPI parcelport for bootstrapping whenever application was started using mpirun
Enable link time constant data folding for VS2013 and above
Enable MPI parcelport by default only if it's enabled at compile time
Simplify cmake script
Adjustments to meet N3721 requirements for when_*

See Issue #794

Signed-off-by: K-ballo <k@fusionfenix.com>
Added error_code support to when_*

Signed-off-by: K-ballo <k@fusionfenix.com>