gradle - commit gradle wrapper output

These artifacts make this repository OS independent and build toolchain
independent. You just need to use `./gradlew` or `gradlew.bat` and
Gradle will install the correct OS-specific version of itself onto your
system.
.gitignore - ignore build artifacts, user-specific gradle files
src - initial commit of source code

Currently everything is hard coded according to the specific
feature engineering required by furiousdigger. Eventually command
line arguments and/or file-based configuration will be able to
configure the feature engineering pipeline on a per-site per-URL
basis.
README.md - initial commit of README