RASAPI interface unit (Delphi conversion by Davide Moretti dave@rimini.com,
ver 2.11) rewritten to link RASAPI32.DLL dynamically via
LoadLibrary/GetProcAddress, preventing application to be terminated
on exception if RAS is not installed.

Original file has been taken from TRASControl version 1.2
(Copyright (c) 1999 by David A. Bussey).

Interface section is not modified. All RASAPI external function declarations
from Implementation section has been deleted. RASAPI functions are linked
dynamically in Initialization section.

Global variable bRasAvail (of type Boolean) indicates if RAS is installed.
If bRasAvail = False, any RASAPI function call returns -1.