hgweb: fix pagination for graph

Keep sessionvars with repository links added in a0843c82d1a2 Without this, e.g. "?style=coal" would be dropped.

Fix test output for updated gitdiffs help and web template cleanups

Do not abort with inotify extension enabled, but not supported by the system. And remove the "native support is required" message which is generated at an inappropriate location and is printed more than once when using 'hg status'.

Enhance gitdiffs help text

Kill trailing whitespace in templates

graphlog: move functions around, eliminate helper function Makes it easier to read all of the code.