rework markdown-unsupported tags. also, always render tag's attrs.
poke #26.
clarify raw output comment
unsupported tags fixups
deeper cfg extend
fix ref lists and multi-call rendering, thanks @RoryH. close #27.
add output tests
if no thead, detect headers in tbody, else make fakes. fix #28.
fix regression; support <b> and <i> again. close #29.
update test output results for table headers
don't iterate arrays using for-in loops. close #30.
fixes lousy libs that add to native prototypes >:(
add demo link & thumb to README
Merge pull request #1 from leeoniya/master

merge yuan