Added python3 support, added lookup utility

[sebimoe]

Python 3 support

I have updated kvg.py and kanjivg.py files to work with both Python 2 and Python 3 (tested 2.7 and 3.9).

XML Handler Fixes

I have updated KanjisHandler and SVGHandler XML-parsing classes in kanjivg.py to work on the current SVG/XML structure. I may have been confused by them, but I could not get them to work, so I rewrote some functionality.

• In case of SVGHandler the changes were limited to accounting for the parent StrokePaths group and ignoring it.
• In case of KanjisHandler the changes involved re-writing how it processes each kanji in turn, as I could not figure out how it was meant to be used.

New command-line utility

I added a utility for displaying a summary of a character based on SVG or XML files. It is useful for checking that the SVGHandler and KanjisHandler classes work correctly at first glance. It is also an example of how to use XML parsing.

$ python .\kvg-lookup.py            
Usage: .\kvg-lookup.py <find-svg|find-xml> <element1> [...elementN]

Recognized commands:
  find-svg      Find and view summary of an SVG file for the given
                element in ./kanji/ directory.
  find-xml      Find and view summary of a <kanji> entry for
                the given element from ./kanjivg.xml file.

Parameters:
  element           May either be the singular character, e.g. 並 or its
                unicode code-point e.g. 4e26.

Examples:
  .\kvg-lookup.py find-svg 並      Will list SVG files describing given character.
  .\kvg-lookup.py find-xml 4e26    Will list <kanji> entry for the same character.

$ python .\kvg-lookup.py find-svg 香  
Found 2 files matching ID 09999

File ./kanji/09999-Kaisho.svg (1/2):
Character summary: 09999 (香) - variant: Kaisho
- group 香
    - group 禾 (top)
        - group 丿 (top)
            - strokes: ㇒
        - group 木 (bottom)
            - strokes: ㇐ ㇑ ㇒ ㇏
    - group 日 (bottom)
        - strokes: ㇑ ㇕a ㇐a ㇐a


File ./kanji/09999.svg (2/2):
Character summary: 09999 (香)
- group 香
    - group 禾 (top)
        - group 丿 (top)
            - strokes: ㇒
        - group 木 (bottom)
            - strokes: ㇐ ㇑ ㇒ ㇏
    - group 日 (bottom)
        - strokes: ㇑ ㇕a ㇐a ㇐a

[benkasminbullock]

Thanks @sebimoe, it's great to have support for both Pythons, and the utility looks handy.