Merge pull request #6 from walu/master

merge with walu
修改了一些语句
Merge pull request #35 from goosman-lei/master

新增第15章翻译内容
Merge pull request #36 from goosman-lei/master

新增第16章翻译内容
ch 14 finished.
fix links.
Merge pull request #37 from goosman-lei/master

新增第17章翻译内容
add contributor.m
Merge branch 'master' of github.com:walu/phpbook
add wenjun s weibo url.
Merge pull request #7 from walu/master

merge with walu
chapter 18-20 transfer finished
fix some bug
Merge pull request #38 from wenjun1055/master

chapter 18-20 transfer finished
update index and preface
upgrade .
upgrade laruence s info
Merge pull request #8 from walu/master

merge with walu
add chapter 19 20 url
Merge pull request #39 from wenjun1055/master

add chapter 19 20 url