Provide better access to existing functions and dialogs

Autocad currently has a lot of dialog boxes that are not accessible from VLISP. This ends up forcing the writing of what should be unnecessary code.

For example, I would like to be able to get the current surface. As it is, I had to write my own code to check for a current surface; if there wasn't one, check for existing surfaces in the drawing; if any surfaces exist, pop up a dialogue box to ask the user to select a current surface; and, finally, return the current surface. This is all something I see other Autocad commands do all the time. I'd like access to things like this, so I don't have to "reinvent the tire", since Autocad would only let me use the wheel...