This value is queried on each comparison of split or txn sort function,
which means it is called quite a lot. Avoiding the KVP lookup of this
property gains a lot in terms of CPU cycles.
It is split into
- /libgnucash (for the non-gui bits)
- /gnucash (for the gui)
- /common (misc source files used by both)
- /bindings (currently only holds python bindings)
This is the first step in restructuring the code. It will need much
more fine tuning later on.