Merge pull request d3#761 from jasondavies/time-en_GB

Add en_GB locale for d3.time.format.

src/time/format-en_GB.js

@@ -0,0 +1,14 @@
+// The date and time format (%c), date format (%x) and time format (%X).
+var d3_time_formatDateTime = "%a %b %e %H:%M:%S %Y",
+    d3_time_formatDate = "%d/%m/%y",
+    d3_time_formatTime = "%H:%M:%S";
+
+// The weekday and month names.
+var d3_time_days = d3_time_daySymbols,
+    d3_time_dayAbbreviations = d3_time_days.map(d3_time_formatAbbreviate),
+    d3_time_months = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"],
+    d3_time_monthAbbreviations = d3_time_months.map(d3_time_formatAbbreviate);
+
+function d3_time_formatAbbreviate(name) {
+  return name.substring(0, 3);
+}