buflib: Refactor various debugging features

Gate buflib_get_data() checking, debug printing, and buflib
integrity checks behind individual defines in buflib.h, and
turn them all off by default. If needed, they can be turned
on manually when compiling.

The buflib debug menu is only available if debug printing is
enabled, so after this commit it will no longer be included
in normal builds -- it isn't very useful to end users.

Change-Id: Iab25b7852bc7c5592ce04c9c45762046a87d5bc3

apps/debug_menu.c

@@ -496,6 +496,7 @@ static bool dbg_buffering_thread(void)
 #undef STR_DATAREM
 }
 
+#ifdef BUFLIB_DEBUG_PRINT
 static const char* bf_getname(int selected_item, void *data,
                                    char *buffer, size_t buffer_len)
 {
@@ -536,6 +537,7 @@ static bool dbg_buflib_allocs(void)
     info.timeout = HZ;
     return simplelist_show_list(&info);
 }
+#endif /* BUFLIB_DEBUG_PRINT */
 
 #if (CONFIG_PLATFORM & PLATFORM_NATIVE)
 static const char* dbg_partitions_getname(int selected_item, void *data,
@@ -2619,7 +2621,9 @@ static const struct {
 #ifdef PM_DEBUG
         { "pm histogram", peak_meter_histogram},
 #endif /* PM_DEBUG */
+#ifdef BUFLIB_DEBUG_PRINT
         { "View buflib allocs", dbg_buflib_allocs },
+#endif
 #ifndef SIMULATOR
 #if CONFIG_TUNER
         { "FM Radio", dbg_fm_radio },