COMP: Ensure LibArchive is not built against unexpected library

LibArchive does a wide search of the build system for any
possible supported archival libraries (BZip2, LibXml2, Expat, Lzma).
This can add unnecessary requirements for end users, so disable
all the optional components that are not needed by Slicer.

Thanks to Hans Johnson for suggesting this change.

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22008 3bd1e089-480b-0410-8dfb-8563597acbee