FIXMEs

* QTableWidget in QDialog for adding tasks/clients: [DONE]
      o Problem: Every time a task is added, it is necessary to click on the client again in order for the QTableWidget to display a new empty line where to add another new task.
      o Solution: Every time a new task is added, a new empty editable line in the QTableWidget needs to be displayed. 

* QComboBox in QDialog for adding tasks/clients: [DONE]
      o Problem: When clicking on "Add new client" item, the combobox will be set to editable and a QLineEdit will replace the on clicked item. If user clicks right after this on another item (client name) in the combobox, and no client is typed, and no return key is pressed, the app crashes and gives a SEGMENTATION FAULT. Controlling editable QComboboxes is painfull :). This happens, because QComboBox sets all items to editable.
      o Solution: Make just "Add new client" item editable.
      o Murray: If it crashes then find out exactly why. First. Use gdb and valgrind. 
      o Problem was: That the QComboBox::activated signal emits internally the QLineEdit::returnPressed signal. Because of the fact that this is not documented, I connected both signals, so every time the QComboBox::activated signal was emitted, my custom slot for managing the QLineEdit::returnPressed signal was called twice (one for the internal behaviour of the QComboBox::activated signal, and another one for the connection I created), triggering a wrong behaviour in the editable property of the QComboBox and causing the segmentation fault.

* QTableView in the main window: [DONE]
      o Problem: Start and End time values do not show in the view. This happens randomly and never with the same input data.
      o Solution: Investigating about this issue, I discovered that the times's QString saved in the .xml file for start and end time, sometimes ends with 4 digits and other times with 5 digits. This problem happens just for the first case. 

* QLineEdit in the main window: [DONE]
      o Problem: Currently allows user to add a new task with no name / no client.
      o Solution: Disable QLineEdit if there are no available tasks.
      o Murray: And, generally, make sure that you check for empty strings at appropriate places in your code. 

* QComboBox in the main window: [DONE]
      o Problem: App does not give information about what to start with.
      o Solution: The combobox could have a default item "Add new task" that will call the QDialog for adding tasks/clients.