New Lua/TikZ-terminal patch for testing

[Peter H. <pe...@af...>]

Hi,

there is a new patch (lua_terminal_rev96_20090329.patch) in the patch tracker
(http://sourceforge.net/tracker/?func=detail&aid=2183264&group_id=2055&atid=302055) 
for testing, that addresses a few things discussed before.

The most important change is the new naming scheme of the Lua terminal:

  * Providing a script or target name is now mandatory. The new syntax:
       set terminal lua <target name> | "<file name>"
                        {<script_args> ...}
    This will look for a script named `gnuplot-<target name>.lua' or
    a script named "<file name>".
  * Support for script names via the environmental variable
    GNUPLOT_LUA_SCRIPT is dropped.
  * The option "script" is obsolete and also removed.
  * Via the environmental variable GNUPLOT_DRIVER_DIR the default search
    directory for target scripts can be changed.

This way adding new target scripts is straightforward. And also using modified 
ones in local directories is still possible and I hope intuitive.

Secondly, the TikZ target's help is now added to the standard documentation 
and can be generated from the script by calling 
 # lua gnuplot-tikz.lua termhelp > gnuplot-tikz.help


Feedback is most welcome!

-Peter