Fixes the pull requests for homebrew/homebrew#26379 by upgrading leptonica to 1.70, patches the pkg-config file, and provides a patch for jbig2enc to allow it to build against leptonica 1.70
Updated whitespace to comply with brew audit
Added testcase for leptonica
Added pkg-config dependency on build
jbig2enc: add 0.28 bottle.
leptonica: add 1.70 bottle.