The node-attribute-parser now marks uris to css and js files as cssresource and jsresource.
Thanks to this, the inspector can open the corresponding files in the style-editor and
debugger rather than just opening a new tab with the source.
This makes use of 2 new toolbox methods: viewSourceInStyleEditor and viewSourceInDebugger.
This first part adds a parser for node attributes which, given some node
information and an attribute name, generates a small AST-like array of
objects that tells which parts of the attribute (if any) are links, and
what they link to.
Using this, the markup-view generates the right HTML structure to display
these parts as links.
This part 1 doesn't yet allow users to follow these links.
