feat(API wrapper): separates implementation from public API

* moves implementation to impl subdirectory
* adds prefix _impl to implementation symbols
* removes double compilation for shared and static libraries
* fixes include guards
* fixes usage of extern "C"

include/wsfs/adapter/authenticate.h

@@ -5,11 +5,19 @@
 #include <stdbool.h>
 #endif
 
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
 struct wsfs_credentials;
 
 typedef bool wsfs_authenticate_fn(
     struct wsfs_credentials * credentials,
     void * user_data);
 
+#ifdef __cplusplus
+}
+#endif
 
 #endif

include/wsfs/adapter/credentials.h

@@ -3,13 +3,13 @@
 
 #include "wsfs/adapter/api.h"
 
-struct wsfs_credentials;
-
 #ifdef __cplusplus
 extern "C"
 {
 #endif
 
+struct wsfs_credentials;
+
 extern WSFSA_API char const * wsfs_credentials_type(
     struct wsfs_credentials const * credentials);
 

include/wsfs/adapter/server.h

@@ -3,14 +3,14 @@
 
 #include "wsfs/adapter/api.h"
 
-struct wsfs_server;
-struct wsfs_server_config;
-
 #ifdef __cplusplus
 extern "C"
 {
 #endif
 
+struct wsfs_server;
+struct wsfs_server_config;
+
 extern WSFSA_API struct wsfs_server * wsfs_server_create(
     struct wsfs_server_config * config);
 

include/wsfs/adapter/server_config.h

@@ -4,13 +4,13 @@
 #include "wsfs/adapter/api.h"
 #include "wsfs/adapter/authenticate.h"
 
-struct wsfs_server_config;
-
 #ifdef __cplusplus
 extern "C"
 {
 #endif
 
+struct wsfs_server_config;
+
 extern WSFSA_API struct wsfs_server_config * wsfs_server_config_create(void);
 
 extern WSFSA_API void wsfs_server_config_dispose(

include/wsfs/adapter/server_protocol.h

@@ -4,14 +4,14 @@
 #include <wsfs/adapter/api.h>
 #include <wsfs/adapter/authenticate.h>
 
-struct wsfs_server_protocol;
-struct lws_protocols;
-
 #ifdef __cplusplus
 extern "C"
 {
 #endif
 
+struct wsfs_server_protocol;
+struct lws_protocols;
+
 extern WSFSA_API struct wsfs_server_protocol * wsfs_server_protocol_create(
     char * mount_point);