Added initial version of AllBrowsersPerSuiteSpec.
Moved web driver creation logic into WebDriverFactory, and make AllBrowsersPerSuite to create web drivers lazily and close the created web driver before proceed to the next one.
Added Html Unit to AllBrowsersPerSuite, and adjusted the name string for web driver.
Added support of explicitly specify browser(s) to run in AllBrowsersPerSuite through config map.
Added scaladoc to describe the behavior of AllBrowsersPerSuite, and some cleanup in imports.
Added AllBrowsersPerTest which creates new instances of all available browsers to run each test.
Bumped version to 0.8.0-SNAP5
Merge branch 'multi-browser' of https://github.com/cheeseng/scalatestplus-play

Conflicts:
	project/ScalaTestPlusPlayBuild.scala
Added a type annotation to two variables and made WebDriverFactory private[play]
Change calls to cancel() to Canceled in withFixture.