Obtain disabled text color on buttons from enabled property

The enabled property on UILabel gives a native and more natural gray color to a disabled button. Using this property cleans up the code a little bit, avoids hardcoding the disabled gray color, and is more in line with the UIAlertView default disabled text color.
Use macro for deprecation of alertViewCancel:
Refactor alert view content configuration
Set alert appearance only once

An alert’s appearance is defined the moment it is shown. Though it can be reconfigured after it is shown, none of these changes will be visible, even if the alert was hidden (due to some other alert showing). That means that changing the alertViewStyle after the alert received the show message will not add or remove text fields, for example. The same applies to buttons. The only thing that can change is title and message labels.
Implement new layout behavior in SDCAlertViewContentView
Use maximumSize property to determine content size

Instead of having a delegate method return the maximum height for the content view’s size, the alert will set the maximumSize property on its content view once it has its own size. This is more in compliance with the "tell, don’t ask" principle.
Determine secure text entry in SDCAlertContentView

Instead of using a delegate method to determine whether the primary text field should use secure entry, that determination is now made in SDCAlertViewContentView
Move button management to SDCAlertViewContentView

Since the alert’s content view displays buttons and needs to keep track of the configuration of the content, moving all button handling to SDCAlertViewContentView makes more sense than doing it in SDCAlertView itself. The public API for SDCAlertView still allows the user to make changes, but the implementation of these methods are simply passed to SDCAlertViewContentView.
Reimplement first other button enabling/disabling

In reimplementing the button logic, this functionality got broken. This commit repairs it and does it the same way UIAlertView does it (which was more elegant than the original implementation).
Reimplement delegate method to original implementation
Fix button behavior mismatch between UIAlertView and SDCAlertView

Buttons are a complete and utter mess on UIAlertView. I find the logic behind it questionable, but I believe the behavior is now the same.
Define text field placeholders earlier

Previously, the text fields’ placeholders were defined right before in a call tree started by -[SDCAlertView show]. This meant that placeholders set by the user were going to be overridden as soon as the alert was displayed. This problem can be avoided by defining the placeholders as early as possible.
Fix minor UI glitch

In a two-button alert, the right button showed a 1px hairline at the bottom
Clean up sample project after testing
Remove unused constants and method
Use UIAppearance for alert styling

The implementation is largely based on jjburka’s initial implementation (https://github.com/jjburka/SDCAlertView/commit/03ff5f0cc8e2803662cdb166002c8ed4079200c1), which caused so many merge conflicts that it was just easier to reimplement.
Update documentation
Update podspec
Merge branch 'master' of https://github.com/Scott90/SDCAlertView

Conflicts:
	SDCAlertView/SDCAlertView.m