Refactor storing of measured_bw versus Unmeasured=1.

This patch moves the measured_bw field and the has_measured_bw field
into vote_routerstatus_t, since only votes have 'Measured=XX' set on
their weight line.

I also added a new bw_is_unmeasured flag to routerstatus_t to
represent the Unmeasured=1 flag on a w line.  Previously, I was using
has_measured_bw for this, which was quite incorrect: has_measured_bw
means that the measured_bw field is set, and it's probably a mistake
to have it serve double duty as meaning that 'baandwidth' represents a
measured value.

While making this change,I also found a harmless but stupid bug in
dirserv_read_measured_bandwidths: It assumes that it's getting a
smartlist of routerstatus_t, when really it's getting a smartlist of
vote_routerstatus_t.  C's struct layout rules mean that we could never
actually get an error because of that, but it's still quite incorrect.
I fixed that, and in the process needed to add two more sorting and
searching helpers.

Finally, I made the Unmeasured=1 flag get parsed.  We don't use it for
anything yet, but someday we might.

This isn't complete yet -- the new 2286 unit test doesn't build.

1 files changed, 4 insertions, 3 deletions

diff --git a/src/or/or.h b/src/or/or.h
index d53d9ae6c8..620b0baf46 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -2072,9 +2072,8 @@ typedef struct routerstatus_t {
 
   unsigned int has_bandwidth:1; /**< The vote/consensus had bw info */
   unsigned int has_exitsummary:1; /**< The vote/consensus had exit summaries */
-  unsigned int has_measured_bw:1; /**< The vote/consensus had a measured bw */
-
-  uint32_t measured_bw; /**< Measured bandwidth (capacity) of the router */
+  unsigned int bw_is_unmeasured:1; /**< This is a consensus entry, with
+                                    * the Unmeasured flag set. */
 
   uint32_t bandwidth; /**< Bandwidth (capacity) of the router as reported in
                        * the vote/consensus, in kilobytes/sec. */
@@ -2318,6 +2317,8 @@ typedef struct vote_routerstatus_t {
                    * networkstatus_t.known_flags. */
   char *version; /**< The version that the authority says this router is
                   * running. */
+  unsigned int has_measured_bw:1; /**< The vote had a measured bw */
+  uint32_t measured_bw; /**< Measured bandwidth (capacity) of the router */
   /** The hash or hashes that the authority claims this microdesc has. */
   vote_microdesc_hash_t *microdesc;
 } vote_routerstatus_t;