refactor Sps generation
parse only add and UT
Merge pull request #1542 from sijchen/review

[Encoder] refactor Sps generation: passed review at https://rbcommons.com/s/OpenH264/r/930/
Merge pull request #1547 from huili2/ParseDecode

parse only add and UT: passed reviewed at https://rbcommons.com/s/OpenH264/r/910/
    add one more conditin for statistics printing to avoid timestamp problem
add EC MV copy
Merge pull request #1548 from sijchen/after_review

[Encoder] add one more condition for statistics printing to avoid potential timestamp problem
Merge pull request #1549 from dongzha/ECMvCopy

add EC MV copy
    add parentness
Initialize the bParseOnly field in DecoderInterfaceTest::TestInitUninit

This fixes valgrind warnings about using uninitialized data
in this test.
    add maxbitrate verification
Merge pull request #1551 from sijchen/after_review2

    add parentness
Merge pull request #1552 from mstorsjo/init-parameters

Initialize the bParseOnly field in DecoderInterfaceTest::TestInitUninit
Explicitly cast int64_t to float

This fixes warnings when bulding with MSVC.
Merge pull request #1554 from mstorsjo/add-float-cast

Explicitly cast int64_t to float
Merge pull request #1553 from ruil2/max2

    add maxbitrate verification
comment output info with FREEZE
add parse only comment in API
remove some unused code
add timestamp in decoder