Bug 751205 - (Part 1) Refactor site identity popup and doorhanger popup to use common arrow panel container. r=wesj

--HG--
rename : mobile/android/base/resources/layout/site_identity_popup.xml => mobile/android/base/resources/layout/site_identity.xml
Bug 751205 - (Part 2) Un-singleton-ify SiteIdentityPopup. r=wesj
Bug 751205 - (Part 3) Factor out arrow/anchor positioning code to ArrowPopup. r=wesj
Bug 751205 - (Part 4) Rename resources to be more generic for arrow popups. r=sriram

--HG--
rename : mobile/android/base/resources/drawable-hdpi/doorhanger_popup_bg.9.png => mobile/android/base/resources/drawable-hdpi/arrow_popup_bg.9.png
rename : mobile/android/base/resources/drawable-large-hdpi-v11/doorhanger_popup_bg.9.png => mobile/android/base/resources/drawable-large-hdpi-v11/arrow_popup_bg.9.png
rename : mobile/android/base/resources/drawable-large-mdpi-v11/doorhanger_popup_bg.9.png => mobile/android/base/resources/drawable-large-mdpi-v11/arrow_popup_bg.9.png
rename : mobile/android/base/resources/drawable-large-xhdpi-v11/doorhanger_popup_bg.9.png => mobile/android/base/resources/drawable-large-xhdpi-v11/arrow_popup_bg.9.png
rename : mobile/android/base/resources/drawable-mdpi/doorhanger_popup_bg.9.png => mobile/android/base/resources/drawable-mdpi/arrow_popup_bg.9.png
rename : mobile/android/base/resources/drawable-xhdpi/doorhanger_popup_bg.9.png => mobile/android/base/resources/drawable-xhdpi/arrow_popup_bg.9.png