remove unnecessary headers and comments
use the standard accessor to set identifiers for files
move the object dictionary to QSLibrarian

Also removes the defaultSearchSet, since it would just contain the
dictionary’s values.

related to #1625
get existing objects from QSLibrarian
safer access to the object dictionary
turn `parent` into a property of QSObject

This eliminates a dependency on QSLibrarian.
eliminate findDuplicateOrRegisterID

As of dbe8512c31, objects will always be created with a "registered"
identifier.
fix a warning for the objectDictionary property
remove a prototype to eliminate leaks

Introduces a warning when the funciton is called.
silence a debugging message in Release builds
Adds an ivar reference in QSPreferencePane to the NSArray of top-level objects instantiated by the NIB.
Updates the QSPreferencePane to manually use Core Foundation to release the top-level NIB objects, to avoid using the improved 10.8-only NIB-loading method, while still ensuring the top-level objects are properly released when using ARC.
Fix a leak found by the static analyzer
Merge branch 'leaks' of https://github.com/quicksilver/Quicksilver into leaks
fix a leak without introducing a warning

Same fix as bbb7b07332, using code @pjrobertson suggested.
Revert "turn `parent` into a property of QSObject"

This reverts commit dfa6a62f7a9d93d3b15da946320f9c3eed11e5c8.
Transfer ownership correctly on that one.

```
Leak: 0x10e2df330  size=48  zone: DefaultMallocZone_0x100319000   __NSCFString  ObjC  CoreFoundation  "/Volumes/Quicksilver"
	Call stack: [thread 0x106122000]: | start_wqthread | _pthread_wqthread | _dispatch_worker_thread2 | _dispatch_client_callout | _dispatch_call_block_and_release | __42-[QSLibrarian scanCatalogIgnoringIndexes:]_block_invoke QSLibrarian.m:531 | -[QSCatalogEntry scanForced:] QSCatalogEntry.m:577 | -[QSCatalogEntry scanAndCache] QSCatalogEntry.m:526 | QSGCDQueueSync QSGCD.h:33 | _dispatch_barrier_sync_f_invoke | _dispatch_client_callout | __30-[QSCatalogEntry scanAndCache]_block_invoke QSCatalogEntry.m:532 | -[QSCatalogEntry scannedObjects] QSCatalogEntry.m:502 | -[QSDefaultsObjectSource objectsForEntry:] QSDefaultsObjectSource.m:85 | -[QSDefaultsObjectSource addObjectsForKeyList:keyNumber:ofType:inObject:toArray:] QSDefaultsObjectSource.m:102 | -[QSDefaultsObjectSource addObjectsForKeyList:keyNumber:ofType:inObject:toArray:] QSDefaultsObjectSource.m:95 | -[QSDefaultsObjectSource addObjectsForKeyList:keyNumber:ofType:inObject:toArray:] QSDefaultsObjectSource.m:102 | -[QSDefaultsObjectSource addObjectsForKeyList:keyNumber:ofType:inObject:toArray:] QSDefaultsObjectSource.m:118 | -[NDAlias(QSMods) quickPath] NDAlias+QSMods.m:15 | FSCopyAliasInfo | _FSCopyExtendedAliasInfoFromAliasPtr | CFStringCreateWithCString | __CFStringCreateImmutableFunnel3 | _CFRuntimeCreateInstance | malloc_zone_malloc
```
Another wrong ARC bridge.
Merge branch 'master' into leaks
Merge branch 'master' into lookup