Remove leftover include directories

codec/common no longer contains headers, they're all in
codec/common/inc now.
add encoder interface UT for IDR request
Regenerate test/common/targets.mk via the mktargets.sh script as well
Merge pull request #1067 from lyao2/interface_ut_commit

encoder interface UT for temporal layer setting change
Merge pull request #1069 from mstorsjo/generate-targets

Regenerate test/common/targets.mk via the mktargets.sh script as well
Merge pull request #1065 from mstorsjo/remove-old-includes

Remove leftover include directories
Merge remote-tracking branch 'upstream/master' into travis.osx