Packages Metadata

New fields added to debian/control Source stanzas:

• XCS-Cross-Host-Build-Depends: build-depends for cross-compilation.
• XCS-Cross-Host-Depends: cross-build-depends for cross-compilation (-${arch}-cross will be added to packages from this list to obtain actual list of build-depends).
• XCS-Needs-Cross-Toolchain: optional, if it is no, then ${arch}-cross-toolchain won't be added to list of build-dependencies)
• XCS-Cross-Mode: optional, if it is `both', then package will be built both for host/tools and target.