Add JSONB config for useBigIntegerStringAdapter and useBigDecimalStri…

[jgallimore]

…ngAdapter

Following on from #134, could this change be considered?

This should allow this:

final JsonbConfig config = new JsonbConfig().withPropertyNamingStrategy(PropertyNamingStrategy.IDENTITY)
          .setProperty("johnzon.useBigIntegerStringAdapter", "false")
          .setProperty("johnzon.useBigDecimalStringAdapter", "false")
          ;

[jgallimore]

This is actually duplicating this: https://github.com/apache/johnzon/blob/master/johnzon-jsonb/src/main/java/org/apache/johnzon/jsonb/JohnzonBuilder.java#L238-L246, so I'll close this and backport this section to 1.2.x if needed.