return a Failure instead of rethrowing an expection in @test_throws
See: https://github.com/JuliaLang/julia/issues/7051
cosmetics: remove tab, fix alignment
add unit tests for Base.Test. Missing tests for @test_approx_eq, but will open discussion with an issue.
Merge branch 'test_throws_7051' of github.com:sjkelly/julia into sjkelly-test_throws_7051

Conflicts:
	test/Makefile
Merge branch 'sjkelly-test_throws_7051'
Merge branch 'master' of https://github.com/JuliaLang/julia