add parameter and one case in UT
use function pointer as refactoring for further strategy adjustment
add scc rate control
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 pull request #1377 from ruil2/scc_rc_1

add scc rate control
add freely setoption for EC_idc and UT
Merge pull request #1380 from huili2/ec_option_free

add freely setoption for EC_idc and UT