* Add support for edge style
* Update for TODO: support of solid/dotted/dashed edges (attr = 'style')
* Edge styles are defined as var edgeStyles in parseAttributeList().
* Add example for edge styles
Add an editable example for playing DOT edge styles
* Correct typo and remove TODO description
* Correct typo of filename from 'dotEdgeSytles.html' to
'dotEdgeStyles.html'.
* Remove TODO description of the issue for edge style
Yasufumi Ogawa