vim-patch report

generate HTML report of:
  - pull requests via GitHub API
  - merged/pending vim-patches based on version.c

TODO:
  - link to GitHub commits based on
      git log --grep='vim-patch'
  - handle N/A ("not applicable") patches by adding `NA` to version.c comments
Merge pull request #9 from justinmk/vimpatch-report

vim-patch report
vimpatch-report: columnar layout
fix pull request URLs

ref #10
vimpatch-report: handle "NA" patches; formatting
Generate user documentation.