Remove the unused FORMAT_COFF define

Nothing in the project currently sets FORMAT_COFF - the other generic
branch works just fine on windows.
Add a test of encoding multiple spatial layers

This increases the coverage of the unit tests.
Fix the comment in welsEncoderExt.h about the EncodeFrame return value

This was changed in 36d56b6638 in the public api, but the
internal implementation header was missed and left inconsistent.
Merge pull request #528 from mstorsjo/fix-comment

Fix the comment in welsEncoderExt.h about the EncodeFrame return value
Merge pull request #511 from mstorsjo/remove-unused-define

Remove the unused FORMAT_COFF define
Remove an unused error code

I don't see this error code being useful - working slowly hardly
would be a reason for the library to return and fail to do what
it was asked to do, so normal functions would never actually return
this code.
update master to latest and add ut of intraprediction in decoder
Merge pull request #530 from licaiguo/DecoderIntraPredUT

update master to latest and add ut of intraprediction in decoder
modify WELS_CLIP1 to be inline functions
Add missing includes of time.h

This fixes building on MSVC.
remove unncessary cast
Remove an unused gitignore entry

Nothing within this project will generate .ko files.
Merge pull request #531 from mstorsjo/add-missing-includes

Add missing includes of time.h
    fix bug that there is no output in encoder console
Merge pull request #534 from ruil2/encoder_ret

    fix bug that there is no output in encoder console
add scene change detector for further extension
remove black space at lineend
Merge pull request #533 from mstorsjo/remove-unused-gitignore-entry

Remove an unused gitignore entry
Merge pull request #522 from mstorsjo/layered-encoding-test

Add a test of encoding multiple spatial layers
Use .obj as suffix for object files on MSVC

This avoids warnings when linking about "unrecognized source file
type, object file assumed".