Improve the release/debug build system.
Defend against allocation errors whilst indexing.
Fix build with Qt4.
Add proto for external com interface.
First implementation of external com via D-Bus.
Complete DBus external com and quit when another instance is open.
Refactor the dbus module to use a special object for registration.
Complete implementation of inter-instance loading using D-Bus.
Add "multi-instance" and "new-session" command line options.
Prevent reopening an already open file.