int QisLib_InitLib(const char* ProgramDir,const void* DisplayHandle, const void*
		AppContext); [Unix/Linux]
	int QisLib_InitLib(const char* ProgramDir); [Windows]

	ProgramDir : See 'Notes #1'
	DisplayHandle (Display*) : NULL or a handle to the display object used by the program.
		[Unix/Linux only]
	AppContext (XtAppContext): NULL or a handle to the program's application context
		[Unix/Linux only]

	success: 0
	failure: one of the following values :

	-3: License Error. Use QisLib_GetErrorMsg to get the exact license string.
	-4: The file 'colfill.pat' does not exist in ProgramDir or cannot be opened.
	-5: Out of system resource, fill pattern bitmaps cannot be created. [Windows only]
	-6: The file 'gdsfont.shx' does not exist in ProgramDir or cannot be opened.

	- This function initializes QisLib and should be called once, before any QisLib
	functionality is used.
	- No display mode:
	If DisplayHandle is NULL, QisLib is used to get vector data only, no image drawing
	functionality is permitted. Since QisLib uses the X server for drawing, if the
	system has no DISPLAY ($DISPLAY is undefined), no image drawing functionality in
	QisLib will work, DisplayHandle should be set to NULL in this case. If no display
	mode is on, various draw functions will do nothing.
	- If AppContext is not NULL, then QisLib_SetProcessEvents can be used to inform QisLib
	to process events during a busy loop. If this is NULL, QisLib_SetProcessEvents
	should not be used or else it will return an error.
	- For simple applications which don't have an application context, pass NULL for
	- If the program does have an application context but does not want QisLib to process
	events during a busy loop, pass NULL for AppContext.

	1) ProgramDir is the path of the directory that must contain the following files:
	'acs.key', 'colfill.pat', 'gdsfont.shx' and ' [On Unix/Linux] or [On Unix/Linux] or qis.dll [On Windows]'.