[TIMOB-2592] iOS: Errors from Xcode's build.log should be printed in results from builder.py

If any Xcode errors occur from the iOS builder.py (specifically in "install" or "distribute"), the error itself gets saved to build/iphone/build/build.log, but is not printed back to the console. Developer will show an alert dialog of the error output of the process, which ends up being a python stack trace, and not the error itself from Xcode. I can reproduce the problem by using an expired provisioning profile on KitchenSink from the "Run on Device" tab in Developer.

The builder.py call looks like (UUID-XXXX is the UUID of my profile, PROFILE_NAME is it's name. You can get both from Xcode):

/Library/Application\ Support/Titanium/mobilesdk/osx/1.5.0/iphone/builder.py install 4.0 ~/Code/titanium_mobile/demos/KitchenSink org.apcelerator.titanium.kitchensink KitchenSink UUID-XXXX PROFILE_NAME iphone

The python trace looks like:

[ERROR] Error: Traceback (most recent call last):
  File "/Library/Application Support/Titanium/mobilesdk/osx/1.5.0/iphone/builder.py", line 1143, in main
    execute_xcode("iphoneos%s" % iphone_version,args,False)
  File "/Library/Application Support/Titanium/mobilesdk/osx/1.5.0/iphone/builder.py", line 925, in execute_xcode
    output = run.run(args,False,False,o)
  File "/Users/marshall/Code/titanium_mobile/dist/mobilesdk/osx/1.5.0/iphone/run.py", line 31, in run
    sys.exit(rc)
SystemExit: 1

In Developer just the top part of this is clipped in an alert dialog:
https://skitch.com/marshall.law/rffxp/titanium-developer">https://skitch.com/marshall.law/rffxp/titanium-developer

And finally, this is a snip of the actual error output of Xcode which resides in the project's build/iphone/build/build.log:

=== BUILD NATIVE TARGET KitchenSink OF PROJECT KitchenSink WITH CONFIGURATION Release ===
Check dependencies
Code Sign error: Provisioning profile 'XXXX' has expired
[BEROR]Code Sign error: Provisioning profile 'XXXX' has expired
** BUILD FAILED **