Added Installer target to build OS X installer package for Autoindigestion.

Added an external build system target to the Xcode project.  Added
Installer.mk makefile that assembles the executable, launchd plist and man
pages and creates the installer package using the pkgbuild command.
Added product archive installer package with welcome and license pages.

Added product archive package that includes the Autoindigestion component
package.  Moved the location of the component package from $(BUILT_PRODUCTS_DIR)
to $(DERIVED_SOURCES_DIR).  Added Distribution.xml file for productbuild command.
Added Installer/Resources directory with welcome and license html pages.

Updated copyright date to 2013.
Added example vendor plist file to installer.

Renamed "Sample Vendor.plist" to "ExampleVendor.plist" to remove space in
filename to make it more make-friendly and to better match the contents
("Example Inc").

Added commands to installer scripts to unload/load the launchd job.
Added installer plugin to automatically download the Auto-Ingest tool.

The Auto-Ingest tool is provided and maintained by Apple.  The
DownloadAutoingestionPlugin plugin adds an additional pane to the installer
that downloads the Auto-Ingest tool if it is not present.

The DownloadAutoingestionPluginPane class provides the UI for the installer
pane.  The AutoingestionTool class manages downloading and installing the
Auto-Ingest tool.  Currently, downloading is implemented, but the final
step, unzipping the downloaded .zip archive, is not implemented.
Added syslog() calls to add some logging around downloading the Auto-Ingest tool.
Added files from Apple's ZipBrowser sample application.

Full ZipBrowser code is from
http://developer.apple.com/library/mac/#samplecode/ZipBrowser/Introduction/Intro.html#//apple_ref/doc/uid/DTS40007830
Fixed compiler errors and warnings in ZipBrowser source.

Removed references to unused ZipEntryView class.  Removed unneeded
-windowControllerDidLoadNib: method that referenced ZipEntryView.

Fixed ARC error related to NSError out parameter.

Added casts to silence trivial integer truncation warnings related to 64-bit code.
Implemented decompression of downloaded Auto-Ingest tool.

Added DataBuffer class that extends ZipBrowser FileBuffer class and provides
ZipDocument with zip archive data from memory rather than from disk.

Added -setFileBuffer: method to ZipDocument so that a DataBuffer instance can
be set on the ZipDocument directly.  Also added -rootEntry getter method to
expose the root ZipEntry object.

Modified -readEntriesForOperation: and -readFromURL:ofType:encoding:error:
methods to read from the zip archive synchronously rather than using
NSOperation and -performSelectorOnMainThread: calls.

Expanded -connectionDidFinishLoading: method in AutoingestionTool class to
find and decompress the Auto-Ingest tool from the downloaded zip archive.
Added a property for the download URL and split the kAutoingestionPath
constant into separate constants for the directory and filename.
Write Auto-Ingest tool out to disk after extracting it.

Extended -connectionDidFinishLoading: method in AutoingestionTool class to
create a temp folder at /tmp/com.ablepear.autoindigestion.installer and
extract Autoingestion.class there from the downloaded zip archive.

Modified the postinstall script to copy the Autoingestion.class file to
/Library/Autoindigestion and remove the temp folder.  Also changed postinstall
to put the Vendors folder and ExampleVendor.plist file in the admin group
and make them group writable.

Removed commented out code in ZipDocument.m and fixed typo in the preinstall
script.
Chopped out unneeded UI code from ZipDocument.

Changed superclass of ZipDocument from NSDocument to NSObject and removed
instance variables and methods related to unneeded UI functions.

Removed classes ZipDirectoryReadOperation and ZipEntryWriteOperation from
ZipDocument.m.
Removed cruft from -readEntriesForOperation: method in ZipDocument.

Removed unused NSOperation parameter and renamed method to -readEntries.
Changed method to add entries immediately when read rather than using an
NSOperation to add small batches of entries.

Removed now unused -addEntries: method.
Renamed ZipBrowser method -readFromURL:ofType:error:.

Removed unused type parameter, method is now -readFromURL:error:.
Removed NSOperation parameter from -writeEntry:toFileURL:forOperation:error:.

In ZipDocument class, method is now -writeEntry:toFileURL:error:.
The operation parameter was unused.
Modified ZipDocument to read from a given FileBuffer object.

Changed signature of method -readFromURL:error: to -readFromFileBuffer:error:.
The FileBuffer object is now always initialized outside the -read method, so
removed FileBuffer alloc/init and related error handling code.

Removed unneeded -setFilebuffer: method.
Zip archive is always assumed to use UTF8 encoding by default.

Removed the documentEncoding instance variable of ZipDocument, since it was
always set to UTF8.

Inlined single call to -readFromFileBuffer:encoding:error: method.
Changed ZipDocument to return uncompressed entry rather than write it to disk.

Renamed method -writeEntry:toFileURL:error: to -unzipEntry: and made it
return the unzipped entry as a NSData object rather than write it to disk.
Replaced use of FileBuffer with DataBuffer in ZipDocument.

Changed DataBuffer's superclass to NSObject and deleted FileBuffer, since
none of it's implementation was being used, only its interface to ZipDocument.

Changed DataBuffer to copy the NSData it's initialized with.
Moved DataBuffer class into ZipBrowser directory.
Removed empty -close method on DataBuffer.

Renamed variables and methods that used "fileBuffer" to "dataBuffer".
Replaced DataBuffer class with NSData (ZipBrowser) category.

DataBuffer wrapped an NSData and provided only helper methods.