fix detector's coordinate mapping for images smaller than IMAGE_DIM
Properly index windows in detector list mode

Fix iteration over single windows: whether one or more windows are
listed for an image, generate windows as a list.
Moving gh-pages docs to docs/ folder, with script to build them
improved docs-building script
Safer docs/ build process: into own folder
Updated README with doc info
Merge pull request #157 from sergeyk/master

Moving gh-pages stuff to docs/ directory, with script to build and deploy to gh-pages.