*Add following functions:
 - Longest common subsequence between two arrays of String
 - Convert two Stacktrace into a similarity matrix (talking quite
sometime to just compute one matrix)
 - Find the similar and unique pairs of call from the above matrix.
O(n^2 * m)
 - Write a regular expression just to extract calls in a stacktrace.
 
*Add new:
 - A datastructure to store Stact Trace information. (using simple
ArrayList.)
 - Add a test case to verify works that can be done with two Stack
Trace.
*Modify:
- Change the regular expression to get StackTrace