Version 1.0.0 with Acacia Systems Markdown browsing improvements

Add new 'render.deep_readme' config option

When a directory is missing a README, the tree node will display the
nearest README from a parent directory.  If this is a Markdown document
(ie, README.md) then its relative links will all be broken, as the
base URL will be different.

GitList deployments that are mainly used for browsing Markdown
documentation may now set [render] deep_readme=false in config.ini,
to prevent parent README files being rendered in sub-directories.