Create new db UUIDs after -replaceDatabase… call

Otherwise every instance of the app will have the same UUID for its database,
which then creates tons of conflicts storing checkpoints on a remote db server.
Fixes #145
Made -replaceUUIDs: public and gave it a unit test

For #145 (+1 squashed commit)
Squashed commits:
[277ff34] Made -replaceUUIDs: public so afflicted databases can be fixed.

See #145.
Added status code to warning “CBL_ReplicatorManager: Can't create replicator…”
CBLGeometry.h was mistakenly not made public on iOS
Persistent replications (CBL_ReplicatorManager) should run on background thread

Cleaned up the creation of background CBLManagers.
Fixes #147
Delete persistent replication when its source/target database is deleted

This used to work in TouchDB, but regressed a while ago, I think during the conversion
to Couchbase Lite.
Fixes #146
Merged latest from CBL project.
Fixed regression wherein _attachments didn’t get passed to map function

Fixes #148 (I think?)
Improve latency of CBLBatcher

The batcher (used by the replicator) will now pass objects through immediately if no
objects have been processed in its configured delay time.
tl;dr: In a continuous replication, individual changes should be processed sooner,
without the artificial 1.5sec of delay.
FIxes #55
Fixed: Listener was truncating HTTP responses longer than 500kbytes

Fixes #149
Added comments, cleaned up logging in CBLHTTPResponse.
Added property CBLListener.URL [API change!]

Provides an easy way to find out where to connect to the listener.
Added an #include to make Xcode 4.6 happier about the last commit
CBLReplications shouldn’t start automatically. [API change]

Deprecated the existing CBLDatabase methods that create CBLReplications,
and added new equivalent ones that don’t call -start.
Fixes #150.
Added explicit -startPersistentReplications call to CBLManager [API Change]

You can control when persistent replications start, by creating the manager
with the .noReplicator option and then later calling -startPersistentReplications.
Fixes #151
Improved -[CBLListener URL]

Now handles IPv6 addresses.
Also using official API to decode IP addresses to strings.
Implemented doc_ids support in replications

Fixes #102
Fixed memory/thread leakage of CBL_Servers

There was a reference cycle between CBLManager, CBLShared and CBLServer
that kept the CBLServer alive even after all CBLManagers were closed.
CBLServer owns a thread, which was also staying alive.
Also fixed a bunch of leaks in the unit tests where they weren't closing
a CBLManager they created.
Add links to demo apps
Detect if app was built without -ObjC and log a fatal error message.

Fixes #153.