Less CSS 框架发布了 2.2.0 版本，改进记录包括：
- do not apply relative paths to svg-gradient and data-uri functions data-uri output
- using import filename interpolation and import inline together now works
- deprecate the compression option (still works, but outputs a warning unless silent)
- The node version of less now has image-size, image-width, image-height which return the image dimensions of a file
- Fixed an issue that could cause the parse to occur more than once and the callback be called multiple times
- if you are outputting to the console, lessc defaults to silent so warnings do not end up in output
- isunit function supports ” to test if a dimension has no unit
- data-uri function now counts characters after base64 encoding instead of bytes before encoding to determine ie8 support
- fix bug effecting guards on pseudo class selectors
- do not cache on the browser when used with modifyVars
- detection if less does not parse last character in file
- detection of whether a file is css now requires /css, .css, ?css, &css instead of just css. You can still tell less the type of file using import options.
- remove extra new line added to sourcemap entry inline file
- support safari extension
- less.parse now exposes a way to get the AST. We do not recommend you use this unless you need to.