Drop support of interface

[Cheng Xu]

It caused a long time known issue with pgf 3.0 and stops us to upload template to CTAN (#20)

[Cheng Xu]

Fixed by following scripts:

#!/usr/bin/env ruby

require "pathname"

class Fixer
  attr_reader :file
  attr_reader :content

  def initialize(file)
    @file = Pathname.new file
    @content = file.read
  end

  def fix!
    puts "==> Fixing #{file}"
    puts "Global linespread: #{global_linespread}"
    content.gsub! '\pdfpagewidth', '\pagewidth'
    content.gsub! '\pdfpageheight', '\pageheight'
    content.gsub! '\usepackage{interfaces-LaTeX}' + "\n", ""
    content.gsub! '\RequirePackage{interfaces-LaTeX}' + "\n", ""
    content.gsub! 'Use \pkgurl{interfaces} package to handle font size and line spread. ', ""
    content.gsub! 'Use \href{http://mirrors.ctan.org/help/Catalogue/entries/interfaces}{\texttt{interfaces}} package to handle font size and line spread. ', ""
    content.gsub! '\RequirePackage[all]{xy}' + "\n", ""
    content.gsub! /[^\n]*xypic[^\n]*\n/m, ""
    content.gsub! '\tl_expandable_lowercase:n', '\str_fold_case:n'
    change_font_cmds = content.scan(/\\changefont{[^}]*}/)
    change_font_cmds.each do |cmd|
      fix_change_font_cmd(cmd)
    end
    file.write content
  end

  def global_linespread
    @global_linespread ||= content[/We set global line spread to (\d\.\d)./, 1].to_f
  end

  def fix_change_font_cmd(cmd)
    size = cmd[/size=([^,}]*)/, 1]
    if size
      raise "Unknown size unit #{size}" unless size.end_with? "pt"
      size_f = size[0...-2].to_f
    end

    linespread = cmd[/linespread=([^,}]*)/, 1]

    new_cmd = if size && linespread
      "\\fontsize{#{size}}{#{(size_f * linespread.to_f).round(1)}pt}\\selectfont"
    elsif size
      "\\fontsize{#{size}}{#{(size_f * global_linespread).round(1)}pt}\\selectfont"
    elsif linespread
      "\\linespread{#{linespread}}\\selectfont"
    else
      ""
    end
    puts "#{cmd} -> #{new_cmd}"
    content.gsub! cmd, new_cmd
  end
end

ROOT = Pathname.new "/Users/xucheng/dev/git/hust-latex"
Pathname.glob(ROOT/"**/*.dtx") do |dtx|
  Dir.chdir(dtx.parent.parent) do
    system "git checkout ."
  end
  fixer = Fixer.new dtx
  fixer.fix!
  message = <<-EOS
#{dtx.basename(".dtx")}: fix for TeXLive 2016

* remove interfaces
* remove xypic
* other fixes
  EOS
  Dir.chdir(dtx.parent.parent) do
    system "make", "clean"
    system "git", "add", dtx.to_s
    system "git", "commit", "-m", message
  end
end

[Xiaojun Hei]

Very good. Thanks for the update.