Update headers for iOS compatibility

IRCClient.h

@@ -18,7 +18,7 @@
  * License for more details.
  */
 
-#import <Cocoa/Cocoa.h>
+#import <Foundation/Foundation.h>
 
 //! Project version number for IRCClient.
 FOUNDATION_EXPORT double IRCClientVersionNumber;

IRCClient/IRCClientChannel.h

@@ -17,7 +17,7 @@
  * License for more details.
  */
 
-#import <Cocoa/Cocoa.h>
+#import <Foundation/Foundation.h>
 #import "IRCClientChannelDelegate.h"
 
 /** \class IRCClientChannel

IRCClient/IRCClientChannelDelegate.h

@@ -17,7 +17,7 @@
  * License for more details.
  */
 
-#import <Cocoa/Cocoa.h>
+#import <Foundation/Foundation.h>
 
 /** @brief Receives delegate messages from an IRCClientChannel.
  *

IRCClient/IRCClientSession.h

@@ -64,7 +64,7 @@
  * </PRE>
  */
 
-#import <Cocoa/Cocoa.h>
+#import <Foundation/Foundation.h>
 #import "IRCClientSessionDelegate.h"
 
 /** @class IRCClientSession

IRCClient/IRCClientSessionDelegate.h

@@ -17,7 +17,7 @@
  * License for more details.
  */
 
-#import <Cocoa/Cocoa.h>
+#import <Foundation/Foundation.h>
 
 @class IRCClientSession;
 @class IRCClientChannel;