[log] Show backtrace on `App.fail` and in verbose mode.
[WatchKit] Honor `xcode_dir` setting from host app.

Fixes http://hipbyte.myjetbrains.com/youtrack/issue/RM-690
[iOS] Pick-up new certificates prefixed with `iOS` instead of `iPhone`.

Fixes http://hipbyte.myjetbrains.com/youtrack/issue/RM-693
reduce compile time by removing `i386' for iOS simulator
remove 'i386' only if build 'x86_64'
remove `i386' at :build:simulator task
[RM-695] add 'application-identifier' to entitlements in order to deploy app to iOS 8.2 beta 3 device

http://hipbyte.myjetbrains.com/youtrack/issue/RM-695
[RM-696] escape Watch app's Entitlements.plist path because it contains white spaces.

http://hipbyte.myjetbrains.com/youtrack/issue/RM-696
[iOS] Do not strip symbols from host that a framework requires.

Fixes http://hipbyte.myjetbrains.com/youtrack/issue/RM-701.
introduce :native parameter for app.vendor_project to include 3rd-party shared libraries
[iOS] Silence `strip` in non-verbose mode.