Don't hardcode an include path to the xcode default toolchain

The necessary system include paths are already inherited, and manually
forcing this location can cause conflicts if using different versions
of xcode installed in parallel.

None of the other xcode projects hardcode this path.
Don't hardcode the sdk on the target level

It's already set on the project level, and this is the default
value anyway.

This was the only project where the sdk was set on the target level.
Abort directly on errors in the unit test in run_Test.sh

Currently it runs all four unit test builds, and an error in any
of the earlier three ones will be missed as long as the fourth one
succeeds.
Silence error logging while running tests that are intended to produce errors

The errors in the test log are distracting, making it look like
a test actually failed.
Updated to match gmp-api changes for Firefox33
Changed gmp-api branch to master and astyled the changes.
Merge pull request #1154 from mstorsjo/runtest-abort-errors

Abort directly on errors in the unit test in run_Test.sh
Merge pull request #1155 from ethanhugg/gmpapi-ff33

Updated to match gmp-api changes for Firefox33
Merge pull request #1147 from mstorsjo/avoid-hardcoded-xcode-paths

Don't hardcode an include path to the xcode default toolchain
Merge pull request #1150 from mstorsjo/unify-sdk-setting

Don't hardcode the sdk on the target level
    add buffer based rc
Merge pull request #1159 from ruil2/scc_rc_1

    add buffer based rc
add interface UT for ForceIntraFrame
remove blank lines
Merge pull request #1162 from sijchen/interfaceUT11

[Encoder] add interface UT for ForceIntraFrame
Remove an unused variable

This fixes build warnings with clang on OS X.
Merge pull request #1153 from mstorsjo/silence-error-testing

Silence error logging while running tests that are intended to produce errors
Merge pull request #1167 from mstorsjo/remove-unused-variable

Remove an unused variable