Update encoderH.lua

Make encoding work with Lua 5.1

The hex escape codes in strings (like "\x7f") were added in Lua 5.2. But before this, decimal escape codes (like "\127") did exists. Replacing the
hex escape codes with decimal ones makes hjson-lua work with Lua 5.1.

Worth noting that \00 does not work in patterns. So this change uses
the %z character class to match character 0x00.

Author: miscbill

hjson/encoderH.lua

@@ -9,28 +9,28 @@ local escape_char_map = {
     ["\t"] = "\\t"
 }
 
-local COMMONRANGE = "\x7f-\x9f" -- // TODO: add unicode escape sequences
+local COMMONRANGE = "\127-\159" -- // TODO: add unicode escape sequences
 
 local function containsSequences(s, sequences)
     for _, v in ipairs(sequences) do if s:find(v) then return true end end
     return false
 end
 
 local function needsEscape(s)
-    return containsSequences(s, {'[\\"\x00-\x1f' .. COMMONRANGE .. "]"})
+    return containsSequences(s, {"%z", '[\\"\001-\031' .. COMMONRANGE .. "]"})
 end
 
 local function needsQuotes(s)
     local sequences = {
         "^%s", '^"', "^'", "^#", "^/%*", "^//", "^{", "^}", "^%[", "^%]", "^:",
-        "^,", "%s$", "[\x00-\x1f" .. COMMONRANGE .. "]"
+        "^,", "%s$", "%z", "[\001-\031" .. COMMONRANGE .. "]"
     }
     return containsSequences(s, sequences)
 end
 
 local function needsEscapeML(s)
     local sequences = {
-        "'''", "^[\\s]+$", "[\x00-\x08\x0b\x0c\x0e-\x1f" .. COMMONRANGE .. "]"
+        "'''", "^[\\s]+$", "%z", "[\01-\08\011\012\014-\031" .. COMMONRANGE .. "]"
     }
     return containsSequences(s, sequences)
 end