add customized javadoc task
fix commons logging javadoc url
add missing package info (a lot more to go)
exclude some packages from javadoc
fix some javadoc warnings
upgrade to Hadoop 1.2.1 and mark it as stable
add initial asciidoctor task
add doc structure (with draft preface)
add requirements page
fix headers level for requirements
adjust preface a bit (still seems to be rendered incompletely)
add apache 2 license
add community page link
refactor intro section
refactor intro section
add layout for core docs
add titles to core docs
minor formatting
minor typo fix
add configuration section