Moved definition of sqlite3_rtree bits and pieces into the correct file.
I guess maybe there is a problem with the pre-processing that is done of all
the SQLite source to generate the fileset that we use.
Adjusted types to match GCC definitions of LIBVM routines.  We'll have to
see if this still compiles correctly in OpenVMS Alpha and I64 (they both use
HP C).
Build description file for SQLite.  This has been tested on VAX with GCC,
but it also needs to build a symbol table/vector for linking the
shareable image.