Fix various display issues

Updates libcspm to a version which properly prettyPrints Seq(Char) and
Char types, and escapes HTML entities when displaying processes to avoid
invalid tags. Also changes Event to be a bit more robust by wrapping it
in a CSPM session.
Adds a context menu to session listing.

It is now possible to launch the inspector directly from the session
listing without having to type directly into the box, using the context
menu.

A hidden bug in the tab code, where updateExprBox would fail when the
current tab is blank, has been revealed by this change and fixed.
Updates tab expression boxes on session load

Now when a session beyond the first is loaded, the session: qualifier is
added, and when a session is closed such that only one session
subsequently remains, the session: qualifier is removed.