Upgrade to ExtJS 5.0.1. Changed theming

- Upgraded ExtJS to 5.0.1 (latest version)
- Changed default theme to 'crisp' (in favor of 'gray') and added 'touch-crisp' in favor of custom 'mobile' theme
- Removed MobileSlider component, because in the latest ExtJS version the default slider works properly on mobile devices (tested on iOS7 & latest Android)
- Disabled MobileCombobox (see line above).
- Added some fixes for iOS7 on iPad