Fix for 1176010: pt-query-digest should know how to group quoted and unquoted database names

t/pt-query-digest/samples/slow057.txt

@@ -0,0 +1,52 @@
+
+# Query 1: 0 QPS, 0x concurrency, ID 0xAA353644DE4C4CB4 at byte 434 ______
+# This item is included in the report because it matches --limit.
+# Scores: V/M = 0.02
+# Attribute    pct   total     min     max     avg     95%  stddev  median
+# ============ === ======= ======= ======= ======= ======= ======= =======
+# Count         50       2
+# Exec time     91    19ms     2us    19ms     9ms    19ms    13ms     9ms
+# Lock time    100     9ms       0     9ms     5ms     9ms     7ms     5ms
+# Rows sent      0       0       0       0       0       0       0       0
+# Rows examine   0       0       0       0       0       0       0       0
+# Query size    65      54      27      27      27      27       0      27
+# String:
+# Databases    db
+# Hosts
+# Users        meow
+# Query_time distribution
+#   1us  ################################################################
+#  10us
+# 100us
+#   1ms
+#  10ms  ################################################################
+# 100ms
+#    1s
+#  10s+
+administrator command: Quit\G
+
+# Query 2: 0 QPS, 0x concurrency, ID 0xCC47B42511EA22DD at byte 662 ______
+# This item is included in the report because it matches --limit.
+# Scores: V/M = 0.00
+# Attribute    pct   total     min     max     avg     95%  stddev  median
+# ============ === ======= ======= ======= ======= ======= ======= =======
+# Count         50       2
+# Exec time      8     2ms   899us   899us   899us   899us       0   899us
+# Lock time      0       0       0       0       0       0       0       0
+# Rows sent      0       0       0       0       0       0       0       0
+# Rows examine   0       0       0       0       0       0       0       0
+# Query size    34      28      14      14      14      14       0      14
+# String:
+# Databases    db
+# Hosts
+# Users        meow
+# Query_time distribution
+#   1us
+#  10us
+# 100us  ################################################################
+#   1ms
+#  10ms
+# 100ms
+#    1s
+#  10s+
+SET NAMES utf8\G