TUN-1350: Enhance error messages with cloudflarestatus.com link, if relevant

vendor/github.com/cloudflare/golibs/lrucache/README.md

@@ -0,0 +1,40 @@
+LRU Cache
+---------
+
+A `golang` implementation of last recently used cache data structure.
+
+To install:
+
+    go get github.com/cloudflare/golibs/lrucache
+
+To test:
+
+    cd $GOPATH/src/github.com/cloudflare/golibs/lrucache
+    make test
+
+For coverage:
+
+    make cover
+
+Basic benchmarks:
+
+    $ make bench  # As tested on my two core i5
+    [*] Scalability of cache/lrucache
+    [ ] Operations in shared cache using one core
+    BenchmarkConcurrentGetLRUCache       5000000               450 ns/op
+    BenchmarkConcurrentSetLRUCache       2000000               821 ns/op
+    BenchmarkConcurrentSetNXLRUCache     5000000               664 ns/op
+
+    [*] Scalability of cache/multilru
+    [ ] Operations in four caches using four cores
+    BenchmarkConcurrentGetMultiLRU-4     5000000               475 ns/op
+    BenchmarkConcurrentSetMultiLRU-4     2000000               809 ns/op
+    BenchmarkConcurrentSetNXMultiLRU-4   5000000               643 ns/op
+
+    [*] Capacity=4096 Keys=30000 KeySpace=15625
+                vitess          LRUCache        MultiLRUCache-4
+    create      1.709us         1.626374ms      343.54us
+    Get (miss)  144.266083ms    132.470397ms    177.277193ms
+    SetNX #1    338.637977ms    380.733302ms    411.709204ms
+    Get (hit)   195.896066ms    173.252112ms    234.109494ms
+    SetNX #2    349.785951ms    367.255624ms    419.129127ms