Added multiple functions prototypes.
Implemented the 'donwload' function.
Implemented the 'install' function.
Renamed the module to getsysint.py.
Updated the module. Now works as: standalone or library.
Multiple fixes.

- Was using the built-in function dir as a variable name.
- Was passing the url as parameter when the directory was the one to
  be passed.
Multiple updates.

- Updated the readme.
- Changed the name of the script to 'download-sysinternals.py'
- Removed unused functions from the script.
- Minor cleanup.
Added a few messages that tell the current state of the process.