compiling devel lyx

[Lars Gullik Bjønnes]

I have investigated a bit on why it is so hard to compile devel lyx.
Two reasons: 

        1. "class LString;" should not be used in headerfiles. Change
           it to "#include "LString.h"

        2. The string class supplied with gcc and egcs are not
           compatible with STL string. So the check we use to decide
           if the included string class should be used of not is
           wrong. We should try to find a better check. We could
           perhaps check if string calls bastring.h or if
           stl/bastring.h exists and if so it is not usable. 

For now configure with --with-included-string.

        Lgb