Added some oblique 45º lines tests

Only the oblique 3 pixels wide lines are defined:
* The oblique 2 pixels wide lines are somewhat hard to define.
* To define the oblique lines wider than 3 pixels we neet to define
  first how the oblique lines should expand their width (realistic or
  exact).
Added tests of hor/ver lines 101px wide

These tests should guarantee that the proportion of the width is
maintained with a margin of error < 1%.
Added tests for lines with 1px slope

This tests are designed to guarantee that the wide lines behave exactly
like normal lines drawn with the Bresenham's algorithm.
This tests are somewhat subjective since this is non-defined behavior,
but I think that mimic the Bresenham's algorithm is reliable enough.

Currently the horizontal version of this test **fail**.