Fix the context-path setup
Ignore temporary data
Fix whitespace
Move validation to jing

Also moved schema validation into a separate namespace to that it can be
reused.

The old validation seemed to have a strange concept of valid. It claimed
that smil files were valid vubis export files. Jing seems to master this
quite well. The downside is that we have another obscure dependency.
Add validation for vubis bulk import
Make DTBook metadata validation robust against xml parsing errors
Merge continuation lines when filtering pipeline output
Use seq when you mean "not empty" instead of seq?