Update project settings to Xcode 5

* Builds 64-bit iOS for 6.0 and above.
Update testing framework to XCTest
Update to Objective-C object subscripting
build for more than just the active architecture
Merge pull request #43 from BillinghamJ/feature-multiple-architectures

build for more than just the active architecture
Prefer ARC-scoped release rather than autorelease in the API

* Creating old entry stream and data is now by convention “ns_returns_retained”, which stops autoreleasing on returning large data (see @f5abe34).
Bitcoin donation address
Update doc comments
Update README
Synthesize a suitable fileMode for MS-DOS or NTFS entries (fix #47)
Remove libc++ dependency

* Build without C++ or Objective-C exception support.

* Use scope guards to cleanup resources instead of @try/@finally blocks.
Composable inflate input streams

* Inflate input streams are now composable with other input streams.

* Provide old archive entry data through single step inflating via [ZZInflateInputStream inflateData:withUncompressedSize:], instead of streaming.

* Encapsulate CGDataProviderRef creation in ZZDataProvider class, dropping non-standard rewind and skipForward methods on ZZInflateInputStream.
Standard (weak) PK decryption support. Basis for future AES decryption support.
proper member functions to manager ZZExtraField
breaking change: remove non-error stream message
moved encryption mode detection from init to local methods
added out keyword to all NSError**
Encrypted property on archive entry instead of archive
Merge pull request #49 from Danielgindi/master

Standard PK (weak) decryption support, with basis for future AES decryption support.
Refactor decrypter classes

* Decrypter classes are now Objective-C protocols/classes instead of C++ abstract/concrete classes. This avoids C++ virtual functions which are unsupported without the libc++ runtime.

* Standard crypto engine is now mostly inlined for performance.

* Encryption mode is now detected early but unsupported decryption errors are only triggered when read is attempted.

* Encryption CRC check moved to check: method.