Returning iOS Version number in capabilities

Fixes #1332
fix changelog
Merge pull request #1527 from penguinho/ios_version

Returning iOS Version number in capabilities
Making default iOS version a string in the capabilities object
Fix 4-inch 64-bit device string building (was missing dash in 64 inch).
Merge pull request #1537 from curtissiemens/master

Fix 4-inch 64-bit device string building (was missing dash in 64 inch).
fail with a nice error message if xcrun can't find instruments (fix #1538)
fix at least one case of ios sims not being killed
cc @penguinho
Merge pull request #1542 from jlipps/master

misc fixes
Fixing get iOS SDK version for Xcode 4
Merge pull request #1543 from penguinho/locale_fix

Fixing get iOS SDK version for Xcode 4
Fixing iosDeviceString for iPad 64-bit case (missing parentheses).
Merge pull request #1544 from curtissiemens/master

Fixing iosDeviceString for iPad 64-bit case (missing parentheses).