Prevent pixelation of small images by displaying it in orignal size by default

[pierrebonny]

Adding small images features.
If image is smaller than container:
-display it in its original size
-hide snap view until it's enough zoomed to be bigger than container

This work has been done to fix (partially) existing issue: #22

Big thank you to Nuno Freire (@nfcf on github) for his two commits used in that fork:
-nfcf@cf76a78
-nfcf@8564e9b

[s-yadav]

Thanks for pulling out this PR. I will check and get this merged.

[Sakkie89]

@s-yadav Is there a possibility that this can be merged any time soon?