anchor.diff:  
   == TODO
   
  -.1.5.0.alpha.13
  -* ensure book chapters and parts start on recto page when @ppbook (using start_new_chapter / start_new_page methods?)
  -  - need a way to add excludes
  -* should we use the term "column" instead of "placement" in running content
  -
  -//--
  +* use <a id=""></a> instead of <a name=""></a> for anchor point in formatted text
  +  - benchmark to see if it's faster to use empty or non-empty element in parser
  +* rename "convert_context_for_" since it can collide with existing blocks
  +* rework resolve_image_path API so it's more logical; override based on type of first argument; document as option
  +* implicit width of inline image calculated incorrectly (see sandbox/issue-494)
  +* QUESTION should we report full image path of gif in warning message?
  +* QUESTION should we add destination to top of imported PDF page?
  +  - import page should accept id as section, optional argument
  +* leading (line height) isn't applied when content is split across pages
   * generate fonts without PS Glyph Names to reduce file size (waiting PR #550 to be marged)
     - create script that can generate fonts entirely from original font source
  -* FIXME if a page is left empty, writing running content on it causes ghostscript to report an error
  -  - problem is no color space is set; can call update_colors to fix
  -  - maybe have a skip_page helper?
  -  - doesn't yet apply since we don't yet insert blank pages in content
  +* if start_new_page is called at end of layout_chapter_title, and media=prepress, ghostscript reports an error
  +  - problem is no color space is set; can fix by calling update_colors before advancing to recto page in start_new_chapter
  +  - maybe introduce a skip_page helper to combine these operations?
   * SIMPLE: document vw/vh measurement units in theming guide (make it clear it only applies in certain cases)
   * SIMPLE: in theming guide, emphasize not using the fallback font when working with very large documents; explain that default theme uses a fallback font
  -* rework resolve_image_path API so it's more logical; override based on type of first argument; document as option
   * document how to test / use a PR
     - see https://github.com/asciidoctor/asciidoctor-pdf/issues/462#issuecomment-246200953
   * FILE ISSUE break printed URIs at each forward slash (and perhaps at ? and & too)
   * add empty? method to Page (instead of page_empty? on document)
   * SIMPLE: add warning that AsciiDoc table cell content is not supported; print as raw source
  -* implicit width of inline image calculated incorrectly (see sandbox/issue-494)
   * FILE ISSUE in prawn-svg not to move cursor (maybe an option?)
   * FILE ISSUE: prevent import_page from adding an extra page; leaves blank page when placing two inserts in a row
     - have import_page first delete current page if page is empty
  +* FILE ISSUE in prawn: go_to_page should accept second argument that is cursor position
   * autowidth causes cells in header row to break word (wraps by char to fit; does not expand table)
  -* dry_run should start at cursor of main document (or as option); total height calculation would need to be revised
  +* UNRESOLVED: dry_run should start at cursor of main document (or as option); total height calculation would need to be revised
  +  - box_height isn't currently accurate when it spans more than one page
     - this should fix height calculation when content is split over a page break (leaving small amount of excess)
  +  - however, if cursor is advanced to fit content on page, then that excess will cause box_height to be too large
  +  - life would be simpler if Prawn allowed us to draw graphics at bottom layer
   * allow height of inline image to be set to line height (perhaps 1em?)
  +* space around inline anchors/index entries doesn't get collapsed by text formatter
   * add support for format attribute on image macro to image-related attributes such as title-page-background-image
     - support explicit image format for cover page image and page background image
   * need some sort of post_construct method for converter that receives document
  
positive.code:   - in fact, must account for every page or else numbering lags behind when scrolling document
  * if we set the vposition on image to a numeric value, it skips the overrun check that happens internally
  * any instance variables referenced by converter methods for inline nodes could get accessed before the converter for document is called
  
  == Potential Optimizations
  
  
negative.code: 
  == Implementation
  
  * should we read SVG file using UTF-8 encoding; or does REXML handle encoding?
  * can we leverage before_rendering_page callback on table?
  * should we use move_past_bottom in some places instead of start_new_page?
  
  === Design
  
  