Pyembroidery

The add_pattern() routine if called directly rather than through the dunder add of pattern + pattern, now gives options for dx, dy, sx, sy, and rotate for translate, scale, and rotate. For pattern appending with transformations.

* PngWriter has guides added.
* A couple corrections to PngWriter.
* PyEmbroidery is turned into a shell references to EmbPattern static calls.
* EmbPattern has init parameters of filename, or EmbPattern.
* EmbPattern has .read() and .write() which accepts settings as direct keyword arguments.

Read PES Headers Versions 7 through 10. Successfully decodes thread data stored in headers from V7-V10 of PES.

Fix additional issues that were not corrected by 1.4.15 with regard to issue 87. ColorBlocks would, if delimited by COLOR_BREAK omit the final stitch.

* Correction for get_as_colorblock() to actually work as expected. (87).
* Added tests to check for corrections.
* Added `repr()` for EmbThread()
* Corrected minor addendum to 83

"MY:" would be written in error as "AY:"