* Adding document describing how to use logger
* Adjusting logs to follow a new guide
* Change order in log header:
line number is now before function name
Fix of the issue that pressing 'Save' when setting
time would set the time indeed, but the UI would
not return to previous window, what might look
as if saving failed.
1. Prepare Pure and Bell specific `Application`
classes and add them to `app` target:
- `products/BellHybrid/apps/Application.cpp`
- `products/PurePhone/apps/Application.cpp`
2. Update `CMakeLists.txt` files.
3. Move `ApplicationBell` implementation to Bell-specific
`Application` class and remove `ApplicationBell` files.
4. Change Bell apps parent classes from `ApplicationBell`
to Bell-specific `Application` class.
5. Rename `Application` to `ApplicationCommon` in the rest of the files.
