Use GetDefaultParams instead of memset to initialize SEncParamExt in the console test app

Most of the default parameters still are overwritten with hardcoded
values in FillSpecificParameters though, but this makes sure that
defaults are applied for any new fields at least.
Use += for all submodules INCLUDE variables

This makes it easier for platform specific makefiles to add
things to some of them. (build/platform-android.mk already does this
for a few submodules, e.g. GTEST_INCLUDES and CODEC_UNITTEST_INCLUDES
already use +=.)
Only force iLoopFilterDisableIdc to 2 if multithreading has been enabled

Previously these lines were within an #ifdef MT_ENABLED block,
but now that threading is enabled by default, we should probably
only do it if threading has been requested.
Debug for Chroma InvHadamard Dequant error
refactor code to eliminate potential div by 0
Simplify the travis configuration, reduce duplicated rebuilds

The -B make option rebuilds everything from scratch - thus a "make -B",
"make -B test" sequence would first build everything from scratch, then
rebuild (almost) everything and run the tests.

The previous sequence, with "make -B test" without specifying
BUILDTYPE=Debug, meant that it rebuilt a new release build instead
and tested that, thus never actually testing the debug build.

This should reduce the time used for compilation in travis runs
to less than half.

Also explicitly specify BUILDTYPE=Release, for clarity.
Merge pull request #1074 from mstorsjo/simplify-travis

Simplify the travis configuration, reduce duplicated rebuilds
Merge pull request #1063 from mstorsjo/unify-makefile

Use += for all submodules INCLUDE variables
Don't pass -L. to the MSVC linker

This avoids warnings - this parameter isn't necessary on MSVC.
Merge pull request #1079 from mstorsjo/linker-flags

Don't pass -L. to the MSVC linker
Modify the unit test for WelsDequantIHadamard2x2Dc
add missing ASM in EC
Merge pull request #1061 from mstorsjo/welsenc-init-defaults

Use GetDefaultParams instead of memset to initialize SEncParamExt in the console test app
Merge pull request #1076 from lyao2/RCdiv

refactor code to eliminate potential div by 0, review at: https://rbcommons.com/s/OpenH264/r/595/
Merge pull request #1060 from mstorsjo/loopfilter-multithreading

Only force iLoopFilterDisableIdc to 2 if multithreading has been enabled
Merge pull request #1080 from huili2/enable_ASM_EC

add missing ASM in EC
Merge pull request #1075 from HaiboZhu/Debug_InvHadamard_Chroma

Debug for chroma inv-hadamard dequant mismatch error
update latest codec