Mega-commit to document the API with doxygen.

Some changes were made to the API when making the documentation:

- A few exported functions are now hidden, because they were only used
  internally in the library.
- A few exported symbols were renamed to document them better than
  previously.
- Cosmetic changes all along the way, as well as some fixes here and there.

--HG--
extra : convert_revision : xtraeme%40gmail.com-20100121021019-onbsivlrhdb7t3ou

lib/repository_sync_index.c

@@ -33,7 +33,13 @@
 #include <xbps_api.h>
 #include "fetch.h"
 
-char SYMEXPORT *
+/**
+ * @file lib/repository_sync_index.c
+ * @brief Repository package index synchronization routines
+ * @defgroup reposync Repository package index synchronization functions
+ */
+
+char *
 xbps_get_remote_repo_string(const char *uri)
 {
 	struct url *url;
@@ -71,7 +77,7 @@ xbps_get_remote_repo_string(const char *uri)
  * Returns -1 on error, 0 if transfer was not necessary (local/remote
  * size and/or mtime match) and 1 if downloaded successfully.
  */
-int SYMEXPORT
+int
 xbps_repository_sync_pkg_index(const char *uri)
 {
 	struct url *url = NULL;