Added functionality to the program

-Added getFormattedKeywords() function to Action.java
-Changed getKeywords() to just return an array of keywords.
-ActionPerformer.java no longer extends Runnable because it does not
need to.
-Add logOnKeyword() function that takes in keywords and logs tweets with
those keywords on the status screen.
-Corrected line spacing issues in GUI.java
-Lines are now correctly deleted from the status window if the line
count exceeds 150.
-The modify window now uses getFormattedKeywords() to display the
keywords in an action.