The tool doesn't work properly if the input/output directory name contains spaces

[dmajda]

If I run helphelp with an input directory argument containing spaces, it will report lot of errors like this:

Resize picture: mogrify -resize 600x5000 out/quickstart/studio-qs-addrepo-import.png
mogrify: unable to open image `out/quickstart/studio-qs-addrepo-import.png': No such file or directory @ error/blob.c/OpenBlob/2588.
mogrify: unable to open file `out/quickstart/studio-qs-addrepo-import.png' @ error/png.c/ReadPNGImage/3639.
cp: target `out/quickstart/studio-qs-addrepo-overview.png' is not a directory

Similarly for the output directory. When the directories don't contain spaces, everything works fine.

The reason is obviously lack of escaping in shell calls.

@bear454: Would you accept a pull request that will resolve this by using Ruby methods (from FileUtils, etc.) instead of shell calls where possible, and using Cheetah in places where they can't be avoided?

[bear454]

Yeah, no problem. Although, long term, Jekyll is probably a better solution than our own.