Add log(x)/log(1000) to Direct formula, 1000^x to Inverse Formula.

For some log scale graph, Increment setting now base on result of direct formula. For example, setting scale as custom formula with direct formula as log(x)/log(1000), direct formula y=0 1 2 should get x =1 1000 1000000. New system variable @CLFT added, default 0, set @CLFT = 1 to apply this change.