Added missing dependency

Currently build would crash with
````
[ERROR] /Users/Peter/github/ShowcaseView/library/src/com/github/espiandev/showcaseview/ShowcaseView.java:[5,26] package android.annotation does not exist
[ERROR] /Users/Peter/github/ShowcaseView/library/src/com/github/espiandev/showcaseview/ShowcaseView.java:[490,10] cannot find symbol
symbol  : class SuppressLint
location: class com.github.espiandev.showcaseview.ShowcaseView
[INFO] 2 errors 
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO] 
[INFO] ShowcaseView (parent) ............................. SUCCESS [1.360s]
[INFO] ShowcaseView (library) ............................ FAILURE [3.704s]
[INFO] ShowcaseView (sample) ............................. SKIPPED
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 6.554s
[INFO] Finished at: Tue May 07 17:05:03 BST 2013
[INFO] Final Memory: 15M/81M
````
Adding above dependency solves the issue
Merge pull request #40 from peter-budo/patch-1

Added missing dependency
Removed sample dependancy on ActionBarSherlock
Only showcase ActionBar if you are on Honeycomb or above
removed env specific detail
Moved all the animation specifics to there own class. Now we could change from nineOldAndroids without affecting the ShowcaseView code
Merge pull request #43 from blundell/encapsulating_animations

new Builder class; moved all the animation specifics to their own class.
Merge pull request #42 from blundell/remove_abs_sample_dependency

Removed sample dependency on ActionBarSherlock
Fix so the Support Library is not needed as this Activity is v14 only. This was done by extending Activity and not FragmentActivity.
Added activity to demonstrate the showcasing multiple action items. Also added the ability to change the showcase's radius.
Added activity to demonstrate the showcasing multiple action items. Also added the ability to change the showcase's radius using setScale
fixed using a custom layout when using builder
Added a dismiss listener to the ShowcaseViews. This will only get fired when the last showcaseView has been dismissed.
Merge pull request #45 from shivgadhia/change_radius_using_scale_and_multiple_showcase_views

Change radius using scale and multiple showcase views
Merge pull request #46 from shivgadhia/adding_dismiss_listeners

Adding dismiss listeners