chore($locale): add quotation marks to reserved keyword "short"

Although the "short" keyword was pulled as a reserved word from ES5, compilers like
YUICompressor still treat it as reserved and may break.

See 7.6.1.1 of ES5 spec for updated reserved words: http://www.ecma-international.org/publications/files/ECMA-ST-ARCH/ECMA-262%205th%20edition%20December%202009.pdf

Closes #5320

Author: kimpettersen

src/ng/locale.js

@@ -53,7 +53,7 @@ function $LocaleProvider(){
         SHORTDAY: 'Sun,Mon,Tue,Wed,Thu,Fri,Sat'.split(','),
         AMPMS: ['AM','PM'],
         medium: 'MMM d, y h:mm:ss a',
-        short: 'M/d/yy h:mm a',
+        'short': 'M/d/yy h:mm a',
         fullDate: 'EEEE, MMMM d, y',
         longDate: 'MMMM d, y',
         mediumDate: 'MMM d, y',