libsepol: export functions for policy analysis

Export functions needed for converting security identifiers from and to
strings and functions computing security server decisions.  These can
be used to debug or run tests on binary policies without running on a
SELinux enabled kernel.

TODO:
These functions have currently a non consistent return behavior: some
are returning -1 on failure and set errno most but not all of the time,
some return a negative errno like value.
Maybe this should be addressed before exporting them?

Acked-by: James Carter <jwcart2@gmail.com>
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>

libsepol/src/libsepol.map.in

@@ -274,3 +274,18 @@ LIBSEPOL_3.0 {
 	cil_write_resolve_ast;
 	cil_set_qualified_names;
 } LIBSEPOL_1.1;
+
+LIBSEPOL_3.4 {
+  global:
+	sepol_av_perm_to_string;
+	sepol_change_sid;
+	sepol_compute_av;
+	sepol_compute_av_reason;
+	sepol_compute_av_reason_buffer;
+	sepol_context_to_sid;
+	sepol_member_sid;
+	sepol_sid_to_context;
+	sepol_string_to_av_perm;
+	sepol_string_to_security_class;
+	sepol_validate_transition_reason_buffer;
+} LIBSEPOL_3.0;