Refactor mikiwindow.py, collect actions into dict, no attribute defined
outside __init__.
In notesEdit, expand tab as 4 spaces.
When Alt pressed, show numbers in viewList. Use Alt+[1-9] to quickly
navigate.
Refactor act() function.
Use QIcon to show numbers in viewedList.
Fix bounding rect of filename in attachmentView.
Use d[key] instead of get(key) to retrieve action from dict, as get(key)
never raises a KeyError.
Able to migrate notebookPath to v0.3.0 folder structure now.
Update Changelog.
Slight fix to attachment.py