core framework state is finally fixed well enough
hat we can turn of the phpunit process isolation.

The patch brings a series of adaptions to use that

* detection of "first test in test file" is simplified
  and is now detected by a static property instead of
  a time based file. This obsoletes the need to delete
  typo3temp/var/tests/functional-* if running tests
  quickly after each other

* methods recentTestInstanceExists() and createLastRunTextfile()
  are obsolete and have been removed

* add proper db connection reset using new core
  methods

* purge singleton state in GeneralUtility and application
  context in between tests

* use Bootstrap::init() as proper main bootstrap
  initialization method instead of picking deeper
  single methods. This allows core to drop other
  boostrap stuff used only by functional test framework
  until now

* turn off process isolation in functional main xml
  and split files