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

bin/xbps-uhelper/main.c

@@ -30,6 +30,7 @@
 #include <errno.h>
 #include <ctype.h>
 #include <assert.h>
+#include <unistd.h>
 
 #include <xbps_api.h>
 
@@ -131,6 +132,8 @@ main(int argc, char **argv)
 	if (argc < 1)
 		usage();
 
+	xbps_init(false);
+
 	plist = xbps_xasprintf("%s/%s/%s", root, XBPS_META_PATH, XBPS_REGPKGDB);
 	if (plist == NULL) {
 		fprintf(stderr,
@@ -314,8 +317,6 @@ main(int argc, char **argv)
 		if (argc != 2)
 			usage();
 
-		xbps_fetch_set_cache_connection(0, 0);
-
 		for (i = 1; i < argc; i++) {
 			rv = xbps_fetch_file(argv[i], ".", false, "v");
 			if (rv == -1) {
@@ -332,5 +333,7 @@ main(int argc, char **argv)
 		usage();
 	}
 
+	xbps_end();
+
 	exit(EXIT_SUCCESS);
 }