Update README.

- Change "Leaf Books" to "Leafbooks".
Ignore build directories.
Add initial project files.

- Add qmake project file.
- Add main() function.
Add the Leafbooks class.
Add the Account class.
Add accounts property to Leafbooks.

- Added dividers to function definitions in leafbooks.cpp.
Add the RootWindow qml file.

- Added the user interface resouce file.
Add interface initialization.

- Add ui resource in the project file.
Register Account and Leafbooks with the QML engine.
Replace ApplicationWindow with LeafbooksWindow.
Add operation functions for the accounts property.

- Add countAccounts, accoutAt, clearAccounts static functions to
  Leafbooks.
- Replaced addAccount with appendAccount in Leafbooks.
- Pass the operation functions to the QQmlListProperty contructor.