in otest-shim, swizzle SenTestLog the same way for app + logic tests.

otest-shim used to have some clownly looking logic to decide when to
swizzle.  It had different paths for app + logic tests, since the test
bundle (which links SenTestingKit) gets loaded differently for each
case.  This fixes it to use the same path for both cases.

Tested with:

```
./xctool.sh -workspace xctool/xctool-tests/TestData/TestWorkspace-Library/TestWorkspace-Library.xcworkspace -scheme TestProject-Library -arch i386 -configuration Debug -sdk iphonesimulator test
```
... for application tests, and...

```
./xctool.sh -project xctool/xctool-tests/TestData/TestWorkspace-Library/TestWorkspace-Library.xcworkspace -scheme TestProject-Library -arch i386 -configuration Debug -sdk iphonesimulator test
```

... for logic tests.
make otest-shim use dyld hooks to wait for SenTestingKit to load.
Merge pull request #2 from facebook/fpotter/otest-shim-cleanup

in otest-shim, swizzle SenTestLog the same way for app + logic tests.