Fix to_json() to not lose precision for values of type double

Also changed a few values in the tests for better numerical diversity.

scripts/base/utils/json.bro

@@ -39,10 +39,11 @@ function to_json(v: any, only_loggable: bool &default=F, field_escape_pattern: p
 		case "count":
 		fallthrough;
 		case "time":
-		fallthrough;
-		case "double":
 		return cat(v);
 
+		case "double":
+		return fmt("%.16g", v);
+
 		case "bool":
 		local bval: bool = v;
 		return bval ? "true" : "false";

testing/btest/Baseline/scripts.base.utils.json/output

@@ -1,10 +1,10 @@
 true
 123
 -999
-1.123457
--1.123456e+308
-0
-1.0
+3.14
+-1.23456789e+308
+9e-308
+1480788576.868945
 "-12.0 hrs"
 "hello"
 ""

testing/btest/scripts/base/utils/json.test

@@ -30,14 +30,14 @@ event bro_init()
 	local i: int = -999;
 	print to_json(i);
 
-	local d1: double = 1.123456789;
-	local d2: double = -1.123456e308;
-	local d3: double = 9.876543e-308;
+	local d1: double = 3.14;
+	local d2: double = -1.23456789e308;
+	local d3: double = 9e-308;
 	print to_json(d1);
 	print to_json(d2);
 	print to_json(d3);
 
-	local t: time = double_to_time(1.0);
+	local t: time = double_to_time(1480788576.868945);
 	print to_json(t);
 
 	local ti: interval = -12hr;