Add support for Big and Little Endian modifiers

This pull request also fixes encoding issues in existing tests caused by upgrading ruby from 1.8.7 to 1.9.3.
@Fryguy, @chessbyte please review.


To prevent duplication can this `if` just be

```ruby
count = modcount if validate_definition_entry_modifier(modifier)
count = count.empty? ? 1 : count.to_i
```