* seperated the Scheduler and Job into seprate go files

* Scheduler Changes
  * refactored the Scheduler into an interface so that we can potentially swap out implementations (see pull #8)
  * changed `Scheduler.Start() chan bool` to `Scheduler.Start()`
  * added `Scheduler.IsRunning()` and `Scheduler.Stop()` to check if the scheduler is running and to stop it from ronning, respectively
  * Renamed `Scheduler.RunAllwithDelay` to `Scheduler.RunAllWithDelay` to match standard syntax
  * Added runPending(time.Time) in order to synchronize all rin loops on the ticker time
  * Added a mutex lock for concurrency support
  * Added default location support at the scheduler lever with `Scheduler.Location(...)`
* Job Changes
  * moved all initialization logic into `init(time.Time)` and `isInit() bool` for code clarity and testability
  * changed `shouldRun() bool` to `shouldRun(time.Time) bool` in order to accept a passed in time from the current ticker iteration, for run loop synchronicity
  * rewrote `At(...)` to parse into a time.Duration
  * added support for intervals greater than 1 for days of the week
  * added `Weekday(time.Weekday)` and made `Sunday()`, `Monday()`, ... alises of it
  * added `time.Location` support on a per job basis
* standardized the comment structure and added some better godoc documentation
* added support for intervals greater than 1 for any weekday with a strongly defined edge case behavior added to the docs
* fixed #4, by removing the panics in Day, Hour, Minute, Second, etc
* added basic test structure
* removed the global `ChangeLoc(...)` method. In favor of setting the default via the scheduler and on a per job baisis

* finish writing tests and make sure they all pass
* write examples
* update ReadMe.md

Author: marksalpeter