SharpCompress can now be used on machines with big endian architecture
such as powerpc. All byte conversions now run through Mono's
DataConverter (or a portable version for builds that don't allow unsafe
code) instead of BitConverter, as BitConverter's behavior depends on the
host cpu.
Fixes broken build in VS2013 introduced by
18bd810228. That commit attempted to fix a
compiler warning from VS2015, but this turns out to be a compiler bug:
https://github.com/dotnet/roslyn/issues/4027 . That commit added code
which VS2013 correctly treats as a compiler warning, breaking the VS2013
build.
I have reverted this unnecessary change to the deflate code, fixing the
VS2013 build, and disabled warning CS0675 on send_bits() which will
satisfy VS2015.
