Merge pull request #122 from kaspergrubbe/master

Made more tests green
Update gemspec and bump version to 3.5.0
Readme typo
Update Readme to inform the ruby 1.9.2-p180 problem
Merge pull request #125 from gschammah/patch-1

Update Readme to inform the ruby 1.9.2-p180 problem
Add external requirements to gemspec.
Merge pull request #126 from mateusg/master

Add external requirements to gem specification (imagemagick / graphicsmagick)
Add the possibility to specify the path where minimagic is installed
Merge pull request #130 from tdgs/master

Add the option to specify the path where imagemagic (or other processors) is installed
Reverse logic, in favour of GraphicsMagick usage if available