Grow maximum count to be at least the count of entries that will fit in a chunk.
Introduce the concept of in use entries.

Entries that are in use are immune from eviction. This concept is needed
to protect the bits that are currently being referenced by a UIImage/CGImageRef
from being overwritten.

Note also that inUse is a refcounted concept since multiple FICImageTableEntry's
can be allocated against the same entityUUID/bits in the backing file.

A side effect of this change is that the imageFormat's maximumCount is no
longer a hard limit since it is possible that all maximumCount entries could
be in use.
Declare an entry in use for the remainder of its lifetime after it is used
with CGDataProviderCreateWithData.
Style change to make release of retained FICImageTableEntry more clear (i.e.
use ARC to perform release rather than explicitly calling CFRelease since
that's what you do with NSObject's).
Improve performance by moving to NSMutableOrderedSet
Attempt to fix unreproducible crasher by replacing NSMapTable with our own weak reference collection.
Pull request: Fix MRU eviction bugs that render the wrong contents for images
Edit
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Introduce the concept of in use entries.

Entries that are in use are immune from eviction. This concept is needed
to protect the bits that are currently being referenced by a UIImage/CGImageRef
from being overwritten.

Note also that inUse is a refcounted concept since multiple FICImageTableEntry's
can be allocated against the same entityUUID/bits in the backing file.

A side effect of this change is that the imageFormat's maximumCount is no
longer a hard limit since it is possible that all maximumCount entries could
be in use.
Fix warning: Implicit conversion loses integer precision: 'unsigned long' to 'CC_LONG'
Merge pull request #33 from jverdi/patch-1

Fix warning: Implicit conversion loses precision: 'unsigned long' to 'CC_LONG'
Fix int precision warnings and 64-bit format args
Merge pull request #34 from jverdi/patch-2

Fix int precision warnings and 64-bit format args
Take #2: Attempt to fix unreproducible crasher. Don't rely on auto-zeroing weak references to know when it's no longer OK to hand back a cached value.
Run deallocBlocks on the FIC dispatch queue so the main thread won't get blocked trying to acquire the FIC lock as an image is deallocated.
Don't crash if mmap fails to map memory
When retrieving an image asynchronously, preheat the data so that the data is paged in and ready to go when the image is eventually drawn.