Beta quality drop of Objective C Support.

- Add more to the ObjC dir readme.
- Merge the ExtensionField and ExtensionDescriptor to reduce overhead.
- Fix an initialization race.
- Clean up the Xcode schemes.
- Remove the class/enum filter.
- Remove some forced inline that were bloating things without proof of performance wins.
- Rename some internal types to avoid conflicts with the well know types protos.
- Drop the use of ApplyFunctions to the compiler/optimizer can do what it wants.
- Better document some possible future improvements.
- Add missing support for parsing repeated primitive fields in packed or unpacked forms.
- Improve -hash.
- Add *Count for repeated and map<> fields to avoid auto create when checking for them being set.
diff --git a/objectivec/GPBCodedInputStream_PackagePrivate.h b/objectivec/GPBCodedInputStream_PackagePrivate.h
index ba6471e..e482b4c 100644
--- a/objectivec/GPBCodedInputStream_PackagePrivate.h
+++ b/objectivec/GPBCodedInputStream_PackagePrivate.h
@@ -114,9 +114,9 @@
 BOOL GPBCodedInputStreamReadBool(GPBCodedInputStreamState *state);
 NSString *GPBCodedInputStreamReadRetainedString(GPBCodedInputStreamState *state)
     __attribute((ns_returns_retained));
-NSData *GPBCodedInputStreamReadRetainedData(GPBCodedInputStreamState *state)
+NSData *GPBCodedInputStreamReadRetainedBytes(GPBCodedInputStreamState *state)
     __attribute((ns_returns_retained));
-NSData *GPBCodedInputStreamReadRetainedDataNoCopy(
+NSData *GPBCodedInputStreamReadRetainedBytesNoCopy(
     GPBCodedInputStreamState *state) __attribute((ns_returns_retained));
 
 size_t GPBCodedInputStreamPushLimit(GPBCodedInputStreamState *state,