Fix RESTORE with line number, add 8 Rosetta Code test programs

RESTORE n now correctly positions past the DATA token so the next
READ gets actual values instead of the token byte.

New tests: Roman numerals, Luhn validator, Towers of Hanoi, 100 Doors,
Pascal's triangle, type declarations, Hailstone sequence, multiplication
table.  50 tests now pass.

tests/programs/pascal_triangle.bas

@@ -0,0 +1,21 @@
+10 REM Pascal's triangle - Rosetta Code
+20 NROWS = 8
+30 DIM R(20)
+40 FOR ROW = 0 TO NROWS - 1
+50   REM Build row right-to-left to avoid overwriting
+60   R(ROW) = 1
+65   IF ROW < 2 THEN 100
+70   FOR J = ROW - 1 TO 1 STEP -1
+80     R(J) = R(J) + R(J-1)
+90   NEXT J
+100  R(0) = 1
+110  REM Print with spacing
+120  PRINT SPACE$(2 * (NROWS - ROW));
+130  FOR J = 0 TO ROW
+140    PRINT USING "####"; R(J);
+150  NEXT J
+160  PRINT
+170 NEXT ROW
+180 REM Verify a known value: row 7, col 3 = C(7,3) = 35
+190 IF R(3) <> 35 THEN PRINT "FAIL: C(7,3) should be 35, got"; R(3) : END
+200 PRINT "Pascal's triangle OK"