adding LaunchXcodebuildTaskAndFeedEventsToReporters()

... which knows how to launch an NSTask that's spewing xcodebuild
output, and then push that output to the reporters.
TitleKey should be defined as 'title' and not 'command'

copy/paste error :-(
renaming 'build_tests_temp' to 'Tests'

... mostly for cosmetic reasons so I can see...

```
=== BUILD-TESTS ===

  xcodebuild build Tests
    TestProject-Library / TestProject-Library (Debug)
      ✓ Check dependencies (56 ms)
```

... in my terminal instead of ...

```
=== BUILD-TESTS ===

  xcodebuild build build_tests_tmp
    TestProject-Library / TestProject-Library (Debug)
      ✓ Check dependencies (56 ms)
```
let's have most of our xcodebuild calls go through the same function...

It will handle sending the 'begin-xcodebuild' event, running xcodebuild
while feeding all the events to the reports, and following up with the
'end-xcodebuild' event.
when xcodebuild fails, print the same error message xcodebuild would show.

Previously, we'd tell you nothing.  Now we'll show something like...

```
=== CLEAN ===

  xcodebuild clean ProjectsWithDifferentSDKs
    OSXLibrary / OSXLibrary (Debug)
      ✓ Check dependencies (50 ms)
      ✓ Remove OSXLibrary.build (1 ms)
      ✓ Remove OSXLibrary.dylib (1 ms)
      ✓ Remove OSXLibrary-Prefix.pch.pth (1 ms)

    iOSLibrary / iOSLibrary (Debug)

  xcodebuild clean Tests
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Failed to build workspace Tests with scheme Tests.
Reason: Scheme "Tests"Tests is not configured for running.
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

** CLEAN FAILED ** (986 ms)
```
fix bug where clean action wasn't cleaning targets set as build for test.

In xctool, we have testables (targets added ot the 'Test' pane of the
scheme editor), and we have buildables for tests (targets added to the
'Build' pane in the scheme editor but with 'Test' checked).

For the clean action, we weren't cleaning the latter (targets marked as
build for test).

Also, might as well unify that logic in XcodeSubjectInfo since we're now
using in the build-tests and clean actions.
errors for run-tests were sometimes being swallowed.

e.g., if the test bundle didn't generate correctly, the output looked
like...

```
  run-test TestProject-LibraryTests.octest (iphonesimulator6.1, logic-test, GC OFF)

** TEST FAILED: 0 of 0 tests passed ** (1167 ms)
```

We had a check that said if the tests failed to run && we got no test
events, pretend things succeeded.  This was to immitate some Xcode
behavior.  But, really, we should only do that when we don't have an
error message.

Now output looks like...

```
  run-test TestProject-LibraryTests.octest (iphonesimulator6.1, logic-test, GC OFF)
  failed: Test bundle not found at:
/Users/fpotter/Library/Developer/Xcode/DerivedData/TestProject-Library-gqcuxcsyguaqwugnnwmftlazxbyg/Build/Products/Release-iphonesimulator/TestProject-LibraryTests.octest
** TEST FAILED: 0 of 0 tests passed ** (1167 ms)
```
a simple test for the 'archive' action.

Just make sure xcodebuild gets invoked with 'archive'
compensate for xcodebuild bug where 'archive' always claims to succeed

xcodebuild's archive action always claims to succeed (with exit status
of 0) even when there are failing build commands.

To compensate, we only claim xcodebuild succeeds when we see no failing
build commands from xcodebuild.
Perform all the writes in close

This fixes the bug reported in issue #64.
fixing -[JUnitReporterTests testTestResults]

@gresrun changed the name used in the <testsuites ...> tag.
Add JSON Compilation Database Reporter
should have a newline after ``` in markdown

This was preventing Marked.app from working.
Added a list of failed tests with standard and error output at the end of the action output. Also added reference numbers similar to footnotes.
adding note about the JUnit reporter
Merge pull request #59 from facebook/jmattdavenport/failed-test-summary

Added a list of failed tests at the end of the action output.
[xctool] otest-query for enumerating test classes in a test bundle
option for parallelizing running of individual test suites inside a target
Only printUsage when -help is present
Merge pull request #69 from bigkm/pr/dont_print_usage_on_error

Only printUsage when -help is present