* Implemented mode and associated tests
* Clarity and complexity changes
* Added google benchmark
* Small changes to mode. More tests.
* Seperated into sorted and non-sorted functions
* Fixed data types and removed copying
* Fixed bounds checking
* Additional tests and cleanup.
* Added tests for std::list and std::forward_list
* Small testing changes and documentation
* Added modes memory allocation and faster insertion
* Changed return type, and modified tests
* Removed copied iterator and edge cases.
* Documentation fixes
