Misc performance improvements for utility functions

lib/imap.utilities.js

@@ -169,12 +169,12 @@ exports.bufferIndexOf = function(buf, str, start) {
       searchLen = search.length,
       ret = -1, i, j, len;
   for (i=start||0,len=buf.length; i<len; ++i) {
-    if (buf[i] == search[0] && (len-i) >= searchLen) {
+    if (buf[i] === search[0] && (len-i) >= searchLen) {
       if (searchLen > 1) {
         for (j=1; j<searchLen; ++j) {
-          if (buf[i+j] != search[j])
+          if (buf[i+j] !== search[j])
             break;
-          else if (j == searchLen-1) {
+          else if (j === searchLen - 1) {
             ret = i;
             break;
           }
@@ -243,8 +243,11 @@ exports.buildSearchQuery = function(options, extensions, isOrChild) {
     if (criteria === 'OR') {
       if (args.length !== 2)
         throw new Error('OR must have exactly two arguments');
-      searchargs += ' OR (' + buildSearchQuery(args[0], extensions, true) + ') ('
-                    + buildSearchQuery(args[1], extensions, true) + ')'
+      searchargs += ' OR (';
+      searchargs += buildSearchQuery(args[0], extensions, true);
+      searchargs += ') (';
+      searchargs += buildSearchQuery(args[1], extensions, true);
+      searchargs += ')';
     } else {
       if (criteria[0] === '!') {
         modifier += 'NOT ';