Added image_filter_crop_offset
improve the document of upstream check module
Merge pull request #396 from lilbedwin/upstream_check_doc

improve the document of upstream check module
"HEAD" method is recommended in upstream check module
Merge pull request #397 from lilbedwin/upstream_check_doc

"HEAD" method is recommended in upstream check module
Merge pull request #380 from Lax/feature/image_filter_crop_offset

Added image_filter_crop_offset
Striped the last linefeed in the resolver file

In CentOS 6.4, the interface gethostbyname can't parse the
nameserver string with extra linefeed.
Merge pull request #400 from yaoweibin/fix_resolver_linefeed

Striped the last linefeed in the resolver file