Reorganise ECC code for inclusion in FIPS module.

Move compression, point2oct and oct2point functions into separate files.

Add a flags field to EC_METHOD.

Add a flag EC_FLAGS_DEFAULT_OCT to use the default compession and oct
functions (all existing methods do this). This removes dependencies from
EC_METHOD while keeping original functionality.

crypto/ec/ec_mult.c

@@ -61,6 +61,8 @@
  * and contributed to the OpenSSL project.
  */
 
+#define OPENSSL_FIPSAPI
+
 #include <string.h>
 
 #include <openssl/err.h>