[Parser] implicit open only p and br tags
Fix perf regression in the Tokenizer : avoid a concatenation

Version 2.3.1 :
-> % node bench2.js
htmlparser2:  01.86 ms/el

Version 3.1.2 without the fix :
-> % node tests/bench.js 
htmlparser2:  04.50 ms/el

Version 3.1.2 with the fix :
-> % node tests/bench.js
htmlparser2:  01.75 ms/el
Merge pull request #54 from abarre/master

[tokenizer] fix perf regression
Merge pull request #52 from AndreasMadsen/implicit-open

[parser] implicit open only p and br tags
3.1.3
[parser] renamed emptyTags to voidElements, sorted them
[parser] improved consistency & simplified
[tokenizer] simplified `end` logic
[tokenizer] removed noop blocks in AFTER_{COMMENT,CDATA}_2
[tokenizer] use `continue` instead of decreasing the index
[bench] removed unnecessary noop functions
[tokenizer] improved handling of remaining data
[readme] it~~'~~s
Add parseDOM and parseFeed helper methods
Merge pull request #55 from ForbesLindesay/patch-1

Add parseDOM and parseFeed helper methods
Add link to live demo
Merge pull request #56 from ForbesLindesay/patch-1

Add link to live demo
[parser] default options & cbs to empty objects

fixes #57
3.1.4
[tokenizer] fix case where `<` followed by whitespace doesn't parse correctly