While loading chunks, check if double values can be represented as integers,

and load them as LIntegers instead of LDoubles if so. Also change test2 so that
it does not fail because of the rounding problem. With these changes, 4 out of
7 test cases in LuaJTest now pass.

src/test/res/test2.lua

@@ -11,7 +11,7 @@ function myfunc(x)
 	return x*x;
 end
 
-print( myfunc(0.1) )
+print( myfunc(0.25) )
 
 do
   local oldMyfunc = myfunc