Log Message:
Update to 1.21. Convert to distutils.mk and add egg.
Fix pkglint warnings.

Changes in 1.21:
 * Add HDF5 saved document format
 * Add filled curve error bar style
 * Add fill left/right options for point plotter
 * Add filetype filters to import dialog file browser dialog
 * In file completer in import dialog, use selected tab as filter
 * Move code to use PyQt new style signals
 * Add a master color setting for xy point and nonorthpoint plot
 * Line labelling algorithm much improved in contour plots, which
   rotates text to match line angle and avoids label overlaps
 * More accurate axis tick label bounding boxes, allowing rotated
   labels to be placed close together
 * Add reflection and rotation options to vector field widget
 * Switch to scientific notation earlier when showing float settings

Bug fixes:
 * Direction combo did not work in import dialog
 * Saving text datasets did not work in Python3
 * Fix partial dataset evaluation issue when loading documents
 * 2D non-regular pixel spaced images give error if clipped in y
 * Handle Unicode quoted characters in simple text data files
 * xcent/ycent in Dataset2D import plugins were ignored
 * promote_tab broken for import plugins
 * Full screen view when all pages are deleted
 * Crash with empty dataset and boxplot widget
 * Fix copy and paste of datasets
 * Python 3 resizing axis bug
 * Crash if picking/zooming on document with no pages
 * Crash if reediting histogram dataset with blank output entry
 * Use end of text formatting string beyond format specifier
 * When writing SVG text as text, use xml:space="preserve" to
   avoid missing whitespace
 * Embedding socket issue on Python 3.4+