Changed pdf's to PDFs.

Just a minor grammatical change.
Changed CustomSort.py to customSort.py

Minor spelling error.
Update README
Added score distribution plot for overall result

Used matplotlib to plot the distribution of scores for Overall Result.
Creating plots for all choices will not be difficult and will be done soon.
Commented out matplotlib commit 1

Users must have the library matplotlib installed in order to get the graphical plot.
Added information about matplotlib

Readme now contains information required by the user before being able to create graphic plots.
Update customSort.py
Fixed sorting of users as per rank

Changed sorted(NAME_DB, ...) to reversed(sorted(NAME_DB, ...))
Update customSort.py
Added feature: User can find his rank directly

Instead of storing all data in a file and then searching, user can directly search for his rank in a particular branch or subject using his Roll Number.
Update customSort.py
Update README
Update customSort.py
Update README
Update customSort.py
Merged modified xennygrimato pull