parse._parsedParameters: do not use helpers.unescapedIndexOf()

iCalendar and vCard parameters do not use \ as escape character in the
property parameter values, hence cn="\"X" is not a quote X, but invalid.
The proper escape character is ^ per RFC 6868.  This change replaces
helpers.unescapedIndexOf(x,…) with x.indexOf(…) in order not to

kewisch#536
ES6-ready

lib/ical/parse.js

@@ -388,9 +388,7 @@ parse._parseParameters = function(line, start, designSet) {
       }
       value = line.slice(valuePos, pos);
       lastParam = line.indexOf(PARAM_DELIMITER, pos);
-      let propValuePos = line.indexOf(VALUE_DELIMITER, pos);
-      // if either no next parameter or delimeter in property value, let's stop here
-      if (lastParam === -1 || (propValuePos !== -1 && lastParam > propValuePos)) {
+      if (lastParam === -1) {
         pos = false;
       }
     } else {

test/parser/property_params.ics

@@ -12,7 +12,6 @@ ATTENDEE;ROLE="REQ-PARTICIPANT;foo";DELEGATED-FROM="mailto:[email protected]";PAR
  TSTAT=ACCEPTED;RSVP=TRUE:mailto:[email protected]
 ATTENDEE;CN=X\:mailto:[email protected]
 ATTENDEE;CN="Y\":mailto:[email protected]
-ATTENDEE;CN="Z\;":mailto:[email protected]
 X-FOO;PARAM1=VAL1:FOO;BAR
 X-FOO2;PARAM1=VAL1;PARAM2=VAL2:FOO;BAR
 X-BAR;PARAM1="VAL1:FOO":BAZ;BAR

test/parser/property_params.json

@@ -93,14 +93,6 @@
       "cal-address",
       "mailto:[email protected]"
     ],
-    [
-      "attendee",
-      {
-        "cn": "Z\\;"
-      },
-      "cal-address",
-      "mailto:[email protected]"
-    ],
     [
       "x-foo",
       {