Added FitTransformer and his test
Hope test is fixed
FitTransformer class
Test. Fix rounded values
Added option 'fill' to keep destination image size as set in maxWidth/maxHeight and fill unused space by given color
Added more checks for arguments
Test for fillBounds
Checking for verticalAlign and horizontalAlign arguments
Image resizes regardless of it's size (bigger or smaller than limits). Callback doesn't create a new image
Test changed to reflect new resizing functionality
Merge pull request #10 from SergeR/FitTransformer

Added FitTransformer and his test