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 release builds of SharpCompress.Test and
SharpCompress.Test.Portable. The UNSIGNED symbol was missing from the
Release configurations of SharpCompress.Unsigned and
SharpCompress.PortableTest
Some RARs with recovery records contain Protect Headers, I've added
support for parsing them so that RARs containing them can be read,
instead of an invalid-header exception being thrown. Parsing logic taken
from unrar reference source.
