Getrstn

Replaces wget

Uses requests instead

Fix san vito related errors

- Fix the problems reading san vito files
- Now cast the column values to int64 instead of int16

Update the API to be more concise and user friendly.

- Enhanced the file reading. Now it'll read all the columns, even if
there's data missing. The number are numpy int16, and the missing data
is numpy NaN.
- Refactored lots of methods of the code. Renamed some methods, and
wrote new ones.

This update is all about code refactoring as the lib was kind of a trap
before this update.

Update documentation

Update the documentation to the numpydoc format, it's much cleaner than the sphinx format. Renames the decompress_file to get_file_content.