Adding more common functions

Functions to:
  * Convert long to int becauseeee arraylist doesn't take a LONG offset.
    brings be to believe if the AL can only contain as many elements as
    is the size of an INTEGER?
  * Get offset in the AL. Moved this here since i'll be using this all
    over the place and writing the calculation in all those places is
    just, well put shikamaru style, menduksena!

ps: Shikamaru is a character from Naruto and Menduksena means that it is
troublesome.
Adding functions to remove

* Remove is a little jhingchak. I can't remove a timestamp somewhere in
  the middle because that would mean I have to restructure the AL. Which
  is really really (really...) expensive. Don't want to go there bro.
* Ergo, added 2 functions - RemoveFrom and RemoveTill that allow a user to
  remove FROM a given timestamp till the end and remove TILL a given
  timestamp from the start. Seemed that this would cover most of the
  necessities.
* Adding tests as well