memory leak in 'reload all'

[Selene ToyKeeper]

The 'reload all' function causes TKDO's process to grow noticably. Also, any function which modifies a task seems to leak a bit too. So, to keep memory use low, it's currently necessary to quit and restart TKDO periodically.

Specifically, the Taskfile.load() function seems to leak. When reloading, it seems as if the old data never gets garbage collected, so memory grows by the size of the task file every time it reloads.

I've tried a bit to fix this, and haven't had much success. I've tried explicitly removing links between parent/child tasks before reloading and destroying the task's text lines, but that only reduced the problem slightly.

While this doesn't generally cause problems, I want to get it fixed because every editing operation in TKDO causes at least one task file to reload after each edit. The general concept is edit, save, then reload... this makes sure all changes get saved to disk immediately, and makes sure the view stays in sync with the actual files. But it also makes memory leak.