Add \langle and \rangle

Auditors: alex

Parser.js

@@ -260,10 +260,12 @@ var copyFuncs = {
     ],
     "open": [
         "open",
+        "\\langle",
         "\\lvert"
     ],
     "close": [
         "close",
+        "\\rangle",
         "\\rvert"
     ],
     "rel": [

buildTree.js

@@ -429,6 +429,7 @@ var charLookup = {
     "\\gets": "\u2190",
     "\\in": "\u2208",
     "\\infty": "\u221e",
+    "\\langle": "\u27e8",
     "\\leftarrow": "\u2190",
     "\\le": "\u2264",
     "\\leq": "\u2264",
@@ -439,6 +440,7 @@ var charLookup = {
     "\\nleq": "\u2270",
     "\\pm": "\u00b1",
     "\\prime": "\u2032",
+    "\\rangle": "\u27e9",
     "\\rightarrow": "\u2192",
     "\\rvert": "|",
     "\\space": "\u00a0",