Initialise z-score of *:score entries to a weighted value

This makes time have some weight in the initial scores in the *:score zsets so a
items can be fetched by the time they were entered in. The time is scaled down
by a factor of 1000000000 so the difference between zsets is single digits.

private/github.rkt

@@ -98,7 +98,9 @@
         (redis-hash-set! c key "url" (feed-commit-url commit*))
         (redis-hash-set! c key "hash" (feed-commit-hash commit*))
         (redis-hash-set! c key "score" "0")
-        (redis-zset-add! c "commit-score:" key 0)
+        (redis-zset-add! c "commit-score:"
+                         key
+                         (/ timeposted/seconds 1000000000.0))
         (redis-zset-add! c "commit-time:" key timeposted/seconds)
         (redis-expire-in! c key (* 7 24 60 60 100))
         (redis-zset-add! c "score:" key 0)])))

private/twitter.rkt

@@ -126,7 +126,7 @@
          c
          "tweet-score:"
          key
-         0)
+         (/ timeposted 1000000000.0))
         (redis-zset-add!
          c
          "tweet-time:"