add copyright/license statement to README
fix output misordering

Always flush text content when writing new content at the end of an
element. I originally wanted to avoid this in the thought that it might
cause sentence breaking to mis-break, but the mixture of immediate and
delayed writing was causing content to be printed after closing tags
that should have followed it.
start implementing table support

Add parsing of table tags. This works for some simple cases, but style
parsing is not yet implemented, and newline suppression of nested
paragraph tags is rather overly effective.

(Keeping simple cells free of newlines is desired, but cells containing
multiple paragraphs also end up with no newlines, which is not. The best
fix would be to break after the <td> tag when the cell contains multiple
paragraphs, indent the paragraphs, and otherwise break normally. However
this is difficult to do with a streaming parser. For now I don't tend to
have tables with large amounts of text in each cell, so it's probably
going to be left as-is for the time being. Eventually this might be
addressed by building a partial DOM of just the table cell contents.)
add parsing of table styles

Add parsing of common style rules for table rows, columns and cells.
This mainly covers tables in .odt's produced by LibreOffice, which seems
to not set properties on tables.
parse parent styles

Modify parsing of inline styles to include reference to parent style.
fix bug in flushText

Fix flushText referring to the wrong variable in non-styled mode.
fix output misordering, take 2

Also flush text content before writing a new tag. See also df9b9a39d66b.