Improve swizzle method code

Signed-off-by: Luca Bernardi <luka.bernardi@gmail.com>
Add method for retrieve the cache directory

Signed-off-by: Luca Bernardi <luka.bernardi@gmail.com>
Fix an issue on isHeadsetPluggedIn method

Signed-off-by: Luca Bernardi <luka.bernardi@gmail.com>
Add [NSArray lbkit_firstObject]

Signed-off-by: Luca Bernardi <luka.bernardi@gmail.com>
Add auto layout helper in UIView's category

Signed-off-by: Luca Bernardi <luka.bernardi@gmail.com>