Changed temporary directory for Sass files
Using string 'node' instead of symbol :node for :lang node finder filter

Why? Because YAML doesn't allow specifying symbols in flow contexts.
Added option tag.meta_info.mi

This is needed when one wants to use the tag like a normal tag,
i.e. by using its correct tag name 'meta_info'.
Added missing config option to list of recognized options for tag.tikz
Fixed pubdate entry in RSS feed template
Moved path handler copy user documentation to website
PathHandler#instance now really always returns the same instance
API doc fix
Prepending 'webgen:' to non-absolute dest_path in virtual path handler to avoid problems in dest path generation
Fixed path selection for 'show tree' command
Add possibility to specify different path when routing to a node

Sometimes it is wanted that a node gets written out to a specific
destination path but when routing to this node another path should
be used. This can now be accomplished with the routing_path meta
information key.

One situation where this is useful is when one wants to create
"nice URLs" where normal pages are represented as directory index
files.
Changed needed argument for node_content and node_meta_info item trackers

The node itself must now be used instead of its alcn.
Refactored Node#proxy_node method
Stated in API doc that only sub-classes of Node are used
Tracking information is now automatically added when routing to a node
Basic website template is now also used when a custom template is used
Added Webgen::Page#to_s
Added missing option node_finder.option_sets
Implemented node finder option reverse for reversing the sort order
Node class can now be specified via the meta information node_class