This allows us to write doctests depending on a ui object, but not on global
configs.
ui.load() is a class method so we can do wsgiui.load(). All ui() calls but
for doctests are replaced with ui.load(). Some of them could be changed to
not load configs later.
Before this patch, the only way to get hgwebdir to honor the recursive paths
was to create a config object or a config file with the recursive paths in it.
This patch makes hgwebdir treat paths the same whether passed in as a list,
tuple, config or however hgwebdir supports passing paths.