- Created a better structure of packages with mocos.data and mocos.views.
 - Changed name of WelcomeActivity to AbsenceActivity.
 - Fixed many good code practices violations (described below) for the
   mocos.data package.

The good code practices mentioned above (and that will be adopted on next
commits are):
	- Correct spacing and lines between statemnts, methods, etc.
	- Creating a convention for names of private fields: m* (all pvt fields
	  starting with a lower case m)
	- One field declaration per line
	- Never exceeding the 100 characters line barrier
	- New line in end of file
	- Encapsulation of fields
Adopting code conventions described also on the mocos.animation package.
Applying code conventions described on the mocos.view package.
Applying code conventions to the classes on the mocos package.
Optimizing imports for all files.
Translating class and field names to English.