make xctool build in Xcode 5

Our old tricks for building iOS dylibs need updating for Xcode 5.

Verified that everything builds in Xcode 4 and Xcode 5 now.  It doesn't
yet run, but it builds.
make xcodebuild-shim work with Xcode5

Xcode3CommandLineBuildLogRecorder became IDECommandLineBuildLogRecorder,
and the signature for the emitSection and finishEmittingClosedSection
changed a little bit.

Tested by running the following with v4 and v5 versions of xcodebuild
(switching via xcode-select).

```
../../../xctool.sh -project TestProject-Library/TestProject-Library.xcodeproj -scheme TestProject-Library -sdk iphonesimulator -arch i386 VALID_ARCHS=i386 test
```
make xcodebuild-fastsettings-shim work with Xcode5

-showBuildSettings works a little different in Xcode 5.  We have to
swizzle a different method to filter out the list of buildables.

Man, I really wish xcodebuild-fastsettings-shim didn't exist.
make Options store build settings as a dictionary

This will make it easier to override values for different build
settings.
workaround to make xcodebuild build w/ the iphonesimulator SDK

Xcode 5's version of xcodebuild has a bug where it won't build iOS
projects against the iphonesimulator SDK.