Implement rule iterators.

Fixes #154.
Merge pull request #175 from wxsBSD/rule_iter

Implement rule iterators.
Implement overloaded functions
Implement "locale" function in PE module and improve buffer bounds checking
Implement module data printing
Fix issues in PE module
Add 'begin_struct_dictionary' and 'end_struct_dictionary'
Update documentation
Fix typos
Fix uninitialized variable warning
Fix uninitialized variable warning