server: gather themes data: - the new LiberviaRootResource's `site_themes` attribute is a set of available themes for a site, it is set a template variable for pages. - if `browser_meta` are available for a theme, the metadata are merged with pages root `_browser` data - if python files are found in `browser_path`, they are added to be handled by brython task.

syntax: glob
*.pyc
*.pyv
*.swp
*.swo
*.js
tags
twistd.log
twistd.pid
sat.egg-info
*.un~
dist
MANIFEST
*.sh
build/
Session.vim
ctags_links/
html/