moved typedefs to beginning of files to solve some include problems

splitted authenticator to have a separate implementation for each auth_method_t
using va_copy to clone va_lists, should fix proplems on AMD64
some other cleanups

src/charon/encoding/generator.h

@@ -24,6 +24,8 @@
 #ifndef GENERATOR_H_
 #define GENERATOR_H_
 
+typedef struct generator_t generator_t;
+
 #include <types.h>
 #include <encoding/payloads/encodings.h>
 #include <encoding/payloads/payload.h>
@@ -31,24 +33,22 @@
 /**
  * Generating is done in a data buffer.
  * This is thehe start size of this buffer in bytes.
- * 
+ *
  * @ingroup enconding
  */
 #define GENERATOR_DATA_BUFFER_SIZE 500
 
 /**
  * Number of bytes to increase the buffer, if it is to small.
- * 
+ *
  * @ingroup enconding
  */
 #define GENERATOR_DATA_BUFFER_INCREASE_VALUE 500
 
 
-typedef struct generator_t generator_t;
-
 /**
  * @brief A generator_t class used to generate IKEv2 payloads.
- * 
+ *
  * After creation, multiple payloads can be generated with the generate_payload
  * method. The generated bytes are appended. After all payloads are added, 
  * the write_to_chunk method writes out all generated data since