Add SignalProtocolC.podspec - CocoaPods support for Apple targets

SignalProtocolC.podspec

@@ -0,0 +1,32 @@
+Pod::Spec.new do |s|
+  s.name         = "SignalProtocolC"
+  s.version      = "0.1.0"
+  s.summary      = "Signal Protocol C Library"
+
+  s.description  = <<-DESC
+                  This is a ratcheting forward secrecy protocol that works in synchronous and asynchronous messaging environments.
+                   DESC
+
+  s.homepage     = "https://github.com/WhisperSystems/libsignal-protocol-c"
+
+	s.license = { :type => 'GPLv3', :text => <<-LICENSE
+                Copyright 2015-2016 Open Whisper Systems
+
+								Licensed under the GPLv3: http://www.gnu.org/licenses/gpl-3.0.html
+
+								Additional Permissions For Submission to Apple App Store: Provided that you are otherwise in compliance with the GPLv3 for each covered work you convey (including without limitation making the Corresponding Source available in compliance with Section 6 of the GPLv3), Open Whisper Systems also grants you the additional permission to convey through the Apple App Store non-source executable versions of the Program as incorporated into each applicable covered work as Executable Versions only under the Mozilla Public License version 2.0 (https://www.mozilla.org/en-US/MPL/2.0/).
+
+                LICENSE
+               }
+  s.author             = { "Open Whisper Systems" => "[email protected]" }
+  s.social_media_url   = "https://twitter.com/whispersystems/"
+
+  s.source       = { :git => "https://github.com/WhisperSystems/libsignal-protocol-c.git", 
+  					 				 :commit => 'b0f0e72159849bd1505d2af510bdd51d8871ce73'}
+
+  s.source_files  = ["src/**/*.{h,c}"]
+  s.exclude_files = 'src/curve25519/ed25519/main'
+  s.public_header_files = ["src/signal_protocol.h", "src/signal_protocol_types.h", "src/curve.h", "src/hkdf.h", "src/ratchet.h", "src/protocol.h", "src/session_state.h", "src/session_record.h", "src/session_pre_key.h", "src/session_builder.h", "src/session_cipher.h", "src/key_helper.h", "src/sender_key.h", "src/sender_key_state.h", "src/sender_key_record.h", "src/group_session_builder.h", "src/group_cipher.h", "src/fingerprint.h"]
+
+  s.xcconfig = { 'HEADER_SEARCH_PATHS' => '$(PODS_ROOT)/SignalProtocolC/src $(PODS_ROOT)/SignalProtocolC/src/curve25519 $(PODS_ROOT)/SignalProtocolC/src/curve25519/ed25519 $(PODS_ROOT)/SignalProtocolC/src/protobuf-c' }
+end