Merge pull request #17 from linkerlin/master

增加了对文件编码的强制限定，限定于UTF-8
update readme version
Merge branch 'master' of github.com:code4craft/webmagic
readme
add a sample
add delay queue
add FilePageModelPipeline
add charset specific for easy call of HttpClientDownloader
add TextContentSelector
fix compile error
syntax hightlight
xsoup test
newselectors
update pom
complete test
refactor in selectors
update
fix grammer error in en
benchmark
add switch