Half-way through a major refactoring of the memory allocation.

I have not even attempted to compile so I am certain there are
countless errors. (CVS 4231)

FossilOrigin-Name: deb7ecd65f7b83eaf0ba610eeef3b0ede61db1c3

src/vdbeInt.h

@@ -219,6 +219,7 @@ struct sqlite3_context {
   Mem *pMem;            /* Memory cell used to store aggregate context */
   u8 isError;           /* Set to true for an error */
   CollSeq *pColl;       /* Collating sequence */
+  sqlite3 *db;          /* Database connection */
 };
 
 /*
@@ -361,6 +362,7 @@ struct Vdbe {
 /*
 ** Function prototypes
 */
+sqlite3 *sqlite3DbOfVdbe(Vdbe*);
 void sqlite3VdbeFreeCursor(Vdbe *, Cursor*);
 void sqliteVdbePopStack(Vdbe*,int);
 int sqlite3VdbeCursorMoveto(Cursor*);