Correct implementation of no_loop()

[tushar5526]

Closes #175

#158 had problem of draw() being called two times if we use no_loop() inside draw() function, which was fixed by a PR by me but it led to #175, that is no_loop() when used in setup() don't call draw() once, as per Processing original documentation

This PR calls draw() once when used in setup() and don't call draw() again if no_loop() is used in draw() again, also I have tested the frame_count for each call and frame_count is being incremented as described by @jeremydouglass in #162 comments,

The issue #158 and #162 is taken care by this PR , I have tested the code for loop(), no_loop(), redraw() for both in setup() and draw() functions and some other codes from examples of p5

But you can test it for some other scenarios too :)

PS : size() when used in setup() along with no_loop() is still buggy, but I don't think it is happening due to no_loop()

[arihantparsoya]

Thanks!