Implementation of append procedure

New features

• Now you can append two EDF file contents into a single one using the Append(x, y Edf) (*Edf, error) function.
• The EDF struct now has some acessible properties to facilitate the access to common data parameters.

Bug fixes

• Reading and writting is now faster due to a better use of buffering techniques.

Known bugs

• The annotations fields are now correctly updated when appending two EDF files.

Creation of EDF struct

For the sake of brevity, the EDF data is now contained in a struct holding the previous header and records variables that should be used by the programmer. These variables are still being used but are "hidden" in this new structure, that enables the use of methods and other improvements.

EDF+ completely implemented for reading

v1.0.0

Maybe there should not be LISP style indentation