Fix warnings

[subdigital]

When building with some unnamed newer SDK, we get a handful of warnings. Namely:

• Use NSTextAlignment instead of UITextAlignment. The enums line up, so it's a safe replacement
• NSString's sizeWithFont: is deprecated
• NSString's drawInRect: is deprecated
• UIView's contentStretch is deprecated

In addition, the demo app won't run b/c the compiler is hard coded to llvm-gcc4.2. I switched this to the default (llvm 5.0 for newer Xcode's and whatever the default is for Xcode 4)

All of the changes have conditional compilation, so it still uses the old way if you're targeting 6 & below.

[jklp]

Hi @subdigital, thanks for the pull request though unfortunately it looks like DCIntrospect is no longer maintained. Good news though, myself and @logicreative have decided to revive DCIntrospect, and created a fork at https://github.com/logicreative/DCIntrospect-ARC to hopefully merge all pull requests and forks back into a single repo.

If you don't mind sending your pull request to the DCIntrospect-ARC repo, we'll try and merge it as quickly as possible. We're also going to be more active with the CocoaPods package manager, so we'll update the latest CocoaPod's podspect once all changes have been merged.

Thanks Jerrold