Improved branch:changelog

                    
|Q            |A   |
|---          |--- |
|Bug Fix?     |y   |
|New Feature? |y   |
|BC Breaks?   |n   |
|Deprecations?|n   |
|Tests Pass?  |y   |
|Fixed Tickets|#124|
|License      |MIT |
|Doc PR       |    |

- [x] Change git log format to include message body
- [x] Change closed issue checking
- [x] Add option to include issues in progress
- [x] Add option to change the format of the output
- [x] Fix the bug of including the same issue multiple times, if multiple commits exist for that issue
- [x] Update tests
- [x] Ask for other ideas