libxbps: ABI/API break due to xbps_pkg{,pattern}_name changes.

The funcs xbps_pkg_name() and xbps_pkgpattern_name() were
using malloc(3) to return the result, until now.

They now have been changed to not allocate the result
via malloc, the caller is responsible to provide a buffer
at least of XBPS_NAME_SIZE (64).

If for whatever reason the pkgname can't be guessed,
returns false. This should avoid lots of small allocs
around libxbps.

New functions have the following prototype:

bool xbps_pkg_name(char *dst, size_t len, const char *pkg)
bool xbps_pkgpattern_name(char *dst, size_t len, const char *pkg)

as suggested by @duncaen.

lib/Makefile

@@ -2,8 +2,8 @@
 
 RANLIB ?= ranlib
 
-LIBXBPS_MAJOR = 4
-LIBXBPS_MINOR = 1
+LIBXBPS_MAJOR = 5
+LIBXBPS_MINOR = 0
 LIBXBPS_MICRO = 0
 LIBXBPS_SHLIB = libxbps.so.$(LIBXBPS_MAJOR).$(LIBXBPS_MINOR).$(LIBXBPS_MICRO)
 LDFLAGS += $(LIBXBPS_LDFLAGS) -shared -Wl,-soname,libxbps.so.$(LIBXBPS_MAJOR)