Update Alert Logic

* by default appium doesn't interact with alerts
* set autoAcceptAlerts to true to have appium accept alerts
Merge pull request #1724 from dandoveralba/alerts

Update Alert Logic
actually allow removeApp to work with selendroid (fix #1686 for real)
cleanup app state before a test too (rewrite of #1732)
cc @dandoveralba @bootstraponline
Fix for installing/removing app on device when a .app path is used.
Merge pull request #1725 from paymand/install_remove_app_ios

Fix for installing/removing app on device when a .app path is used.
Merge pull request #1726 from jlipps/master

cleanup app state before a test too (rewrite of #1732)
fix autoAcceptAlerts undefined issue (cc @dandoveralba)
Use correct suffix (.zip or .apk) when downloading app from a url.

md5calculator (used in lib/devices/android/android-common.js)
can only handle files that end in .ipa or .apk, not .zip.
Currently urls that end in .apk are downloaded as appium-app.zip
Merge pull request #1727 from rectalogic/master

Use correct suffix (.zip or .apk) when downloading app from a url.