PureHTML.TreeBuilder.Modes.InColumnGroup (PureHTML v0.5.0)

HTML5 "in column group" insertion mode.

This mode handles content inside a <colgroup> element within a table.

Per HTML5 spec:

Character tokens:
- Whitespace: insert
- Anything else: close colgroup, reprocess in "in table"
Comments: insert
DOCTYPE: parse error, ignore
Start tags:
- html: process using "in body" rules
- col: insert void element
- template: process using "in head" rules
- Anything else: close colgroup, reprocess in "in table"
End tags:
- colgroup: pop colgroup, switch to "in table"
- col: parse error, ignore
- template: process using "in head" rules
- Anything else: close colgroup, reprocess in "in table"
EOF: process using "in body" rules