Helpers for parsing and rendering canonically.
Haddock markup fixes, and work around #774 in Cabal
Combinator for composing a Router with a PathSpec.

This is needed to build results coming from multiple path
segments.
Export new combinator.
Partial paths
Remove :. again.
result-type polymorphism
Intermediate commit: tests broken but running
Tests pass, hurrah
More doctests
Haddocks
Convenience function, doc updates.
Fix my spelling.
Fix canonIndex
Fix canonIndex.
Leading slash canonicalisation
Change handling of index
Remove need for eos'
note about absolute-form URL normalisation
normalisation, necessary for absolute-path form requests