Remove empty files
Automatically chomp all [%...%] directives

This makes the use of [%-...-%] unnecessary.
Remove unnecessary "Page generated" line
Add multiple output support

This requires turning the outPath columns in the Builds and BuildSteps
tables into separate tables, and so requires a schema upgrade.
Security: Ensure that a build product refers to the Nix store
Security: Also check paths in the web server
Use getMainOutput
Add missing files

Doh!
Builds page: Remove redundant tab titles
Show dependencies as a tree rather than a list
Get rid of unnecessary [%- and -%] tags
Fix indentation and get rid of some unnecessary whitespace in the output
Fix some XML well-formedness problems
Fix query-all-tables test count, there are more tables now
Move <style> to hydra.css
Update jquery/jqueryui
Simplify the log tree implementation a bit

In particular use the :last-child selector, which is non-standard but
supported by all major browsers.
Factor out the tree rendering
Simplify the tree implementation a bit more
Render the dependencies as a tree