Added end_lineno to indicate the last line number in always, module, …

[dyadav7]

This will help in knowing the end line number for always block, modules, statements, case statement.
User can than use this information for different usage:

1. Find the smallest / biggest module
2. Find smallest/biggest always blocks , case statements
3. Use this information to create a new file that has these parts (blocks / modules / ..) commented out.
4. ....

[shtaxxx]

Thanks! Let me review the code.