====== GetTitleDistribution(college,top) ======
Return a sorted list of title which alumnus of this college most get.
====== Description ======
Given a college name, we can find alumnus of this college are common has what title.
====== Parameter ======
  - college: college or university name
  - top: the number of top titles
====== Return ======
A sorted list of compayies
====== Detail Information ======
  - given a college
  - find people who were graduated from this college
  - get people information(pid, name, title)
  - map people information to title
  - count the number of each title
  - sort and show top of title