API clean up (part 2), plus misc changes and improvements.

- Rename regpkgs_dictionary to regpkgdb_dictionary to better describe what is is.
- Change some funcs in plist.c to return a boolean rather than int.
- Hide more internal funcs off the API.
- Simplify xbps_repository_update_pkg() and remove its second arg.
- Hide implementation details in xbps_repository_pool, now to iterate over the
  pool you have to use xbps_repository_pool_foreach and its struct
  repository_pool_index.
- Introduce xbps_{init,end}, to initialize/destroy some stuff in the library.
- Introduce xbps_dbg_printf to printf stuff for debugging purposes.
- xbps-{bin,repo}:  added -d arg to enable debugging output.
- Before checking if a config file needs to be installed or such, check that
  package contains the "conf_files" array.
- Remove obsolete dirs as well while updating packages.
- If transaction dictionary is ready remove the "missing_deps" array.

Bump XBPS_RELVER to 20101118.

--HG--
rename : lib/regpkgs_dictionary.c => lib/regpkgdb_dictionary.c

lib/download.c

@@ -39,7 +39,9 @@
 #include <string.h>
 #include <errno.h>
 #include <fcntl.h>
+
 #include <xbps_api.h>
+#include "xbps_api_impl.h"
 #include "fetch.h"
 
 /**
@@ -191,7 +193,7 @@ xbps_fetch_error_string(void)
 	return fetchLastErrString;
 }
 
-void
+void HIDDEN
 xbps_fetch_set_cache_connection(int global, int per_host)
 {
 	if (global == 0)
@@ -202,7 +204,7 @@ xbps_fetch_set_cache_connection(int global, int per_host)
 	fetchConnectionCacheInit(global, per_host);
 }
 
-void
+void HIDDEN
 xbps_fetch_unset_cache_connection(void)
 {
 	fetchConnectionCacheClose();