Added some missing calls to bind(this).

Hi all.  This request fixes the following errors I encountered:
```
TypeError: Cannot set property 'pageLoadedCbs' of undefined, at appium/app/hybrid/ios/remote-debugger.js:367:28
TypeError: Object #<Glob> has no method 'bind', at IOS.cleanupAppState appium/app/ios.js:404:17
TypeError: Cannot read property '0' of undefined, at null._onTimeout appium/app/ios.js:931:40
TypeError: Cannot read property 'curOrientation' of undefined appium/app/ios.js:1472:17
```