add original application version receipt field
bump version number
fix compiler warning: missing newline at end of file
return nil when the App Store receipt is missing

Fixes a BAD_ACCESS crash that would occur when the App Store receipt
was missing. [DHAppStoreReceipt mainBundleReceipt] now safely returns
nil.
Merge branch 'original-version-receipt-field' of git://github.com/crazile/DHAppleReceiptParser into crazile-original-version-receipt-field

Conflicts:
	DHAppleReceiptParser.podspec