Trying to seperate tools - attempt ONE

Okay, so the intention is to make the tools modular. Currently I am
trying to create a base class named "Tool" which will point to the
objects of concrete classes derived from Tool. Each kind of tool will be
responsible for handling the touchevents by themselves, also to manage
and modify the Paint and Path objects.

For the uber geeks... this is supposed to be something akin to "Bridge"
design pattern.
Seperating Logging Mechanisms - attempt Two

Sorry if this particular commit seems so out of context, but the code
was looking really messy and I was not able to make any further changes
while worrying about it.
Implementing MVC

While trying to seperate tools, I realized it would be very difficult to
keep the tools seperate and modular from the main activity or view class
if we don't loosen up the couping between the components. So, this is
the first step. This code refactoring is incomplete and has introduced
major amount of bugs back in.
Issue with the previous commit fixed

In the previous commit many bugs were introduced. The ones known to me
are :
1. The back button on navigation is non responsive
2. The path you are currently drawing was not visible untill you lift
your finger.

This commit fixes the 2nd issue.
Point Creation now possible

Functionality added : now touching any point and lifting your finger
back marks a point on the canvas.