Allow proportional scaling of thumbnals and images
It was impossible to set with or height to 0 as it then always default settings were used.
This is now possible. Default values are now only used if other than digits are in those parameters.
thumbnail(img, 400, 0, 'r') now gives you as expected an image with height scaled proportional instead of deefualt height.
Merge pull request #1244 from rarila/thumb-resize-bug

Allow proportional scaling of thumbnals and images