add parameter and one case in UT
use function pointer as refactoring for further strategy adjustment
Merge pull request #1374 from sijchen/ref_refac41

[Encoder UT] Add parameter and one case in UT
Merge pull request #1375 from sijchen/ref_refac11

[Encoder] Use function pointer for pEndofUpdateRefList
Merge branch 'master' of https://github.com/cisco/openh264 into ref_refac21

Conflicts:
	codec/encoder/core/src/ref_list_mgr_svc.cpp