use sed instead of grep to get rid of the <?xml...> line

This allows us to parse files with no newlines.
openSUSE-13.1's rpm ignores obsoletes in -i mode

Adapt the pool default to this.
add changes, bump version
fix pool_job2str message for lock ;)
fix access to freed memory if we had to allocate a new schema when serializing a key
adapt repo->end in repo_empty() function
fix basename optimization for STRINGEND

broken with commit 0804020d92975c20a683f490f81339c14555b2d4