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/pkgmatch.c

@@ -27,6 +27,12 @@
 
 #include <xbps_api.h>
 
+/**
+ * @file lib/pkgmatch.c
+ * @brief Package version matching routines
+ * @defgroup vermatch Package version matching functions
+ */
+
 static int
 csh_match(const char *pattern, const char *string, int flags)
 {
@@ -106,8 +112,8 @@ csh_match(const char *pattern, const char *string, int flags)
 	return ret;
 }
 
-int SYMEXPORT
-xbps_pkgdep_match(const char *instpkg, char *pattern)
+int
+xbps_pkgpattern_match(const char *instpkg, char *pattern)
 {
 	const char *fname = instpkg;
 	char basefname[PATH_MAX], condchar = '\0', *condition;