Objective-C literals for NSDictionary, NSArray, and NSNumber

Objective-C literals: one can now create literals for NSArray, NSDictionary, and NSNumber (just like one can create literals for NSString)

NSArray Literals

Previously:

 array = [NSArray arrayWithObjects:a, b, c, nil];

Now:

array = @[ a, b, c ];

NSDictionary Literals

Previously:

dict = [NSDictionary dictionaryWithObjects:@[o1, o2, o3]

  forKeys:@[k1, k2, k3]];

Now:

dict = @{ k1 : o1, k2 : o2, k3 : o3 };

NSNumber Literals

Previously:

NSNumber *number;

number = [NSNumber numberWithChar:'X'];

number = [NSNumber numberWithInt:12345];

number = [NSNumber numberWithUnsignedLong:12345ul];

number = [NSNumber numberWithLongLong:12345ll];

number = [NSNumber numberWithFloat:123.45f];

number = [NSNumber numberWithDouble:123.45];

number = [NSNumber numberWithBool:YES];

Now:

NSNumber *number;

number = @'X';

number = @12345;

number = @12345ul;

number = @12345ll;

number = @123.45f;

number = @123.45;

number = @YES;