Window level higher than normal

When displaying the Toast under status bar the windowLevel is set to `UIWindowLevelNormal`. However, this is not fully correct because this window is on top of the main application window. When using this library with others like `SVProgressHUD`, they have problems identifying the proper place to insert themselves. Just adding a small amount (+1) works and configures this window on proper level (above the app).
Fix bug where +dismissAllNotifications: does not respect the animated flag
Merge pull request #79 from junjie/fix-dismiss-all-animation

Fix bug where +dismissAllNotifications: does not respect the animated flag
Merge pull request #70 from angelolloqui/master

Window level higher than normal
Create CONTRIBUTING.md
Update CONTRIBUTING.md
Update CONTRIBUTING.md
Make documentation for kCRToastStatusBarStyleKey more accurate.

Values for this key should be UIStatusBarStyles, not arbitrary
NSIntegers.
Don't ask travis to update xctool anymore

Travis have upgraded to the latest xctool. Running `brew upgrade xctool` has a failure exit status if it is up to date (handy!). So let's err on the side of upgrade xctool when we start having problems with xctool.
Support for Rubymotion

The NSDictionary that rubymotion creates from hashes doesn't seem to gel well with `indexOfObjectIdenticalTo`, perhaps something to do with the way constants are handled? This change allows CRToast to be used with rubymotion while keeping the valid key checking intact.
Merge pull request #85 from Ashton-W/travis-brew-error

Fix: Don't ask travis to update xctool anymore
Merge pull request #81 from mkantor/more-accurate-status-bar-style-type-documentation

Make documentation for kCRToastStatusBarStyleKey more accurate.
Merge pull request #86 from balvig/rubymotion

Fix for Rubymotion, removed use of `indexOfObjectIdenticalTo:`