Revert "Removed all calls to BitConverter." Alan McGovern has confirmed that Mono does indeed support BitConverter.

This reverts commit 9524b2d45db746b13448a9468bec632a9eed864b.
Revert "Fixed nuget dependencies"

This reverts commit 434730630558f7cfba66d0b8a08852ba24f31cf9.

Conflicts:
	scripts/Mono.Nat.dll.template.nuspec