Properties can be interpolated, e.g. @{prefix}-property: value;
a default function has been added only valid in mixin definitions to determine if no other mixins have been matched
Added a plugins option that allows specifying an array of visitors run on the less AST
Performance improvements that may result in approx 20-40% speed up
Javascript evaluations returning numbers can now be used in calculations/functions
fixed issue when adding colours, taking the alpha over 1 and breaking when used in colour functions
when adding together 2 colours with non zero alpha, the alpha will now be combined rather than added
the advanced colour functions no longer ignore transparency, they blend that too
Added --clean-option and cleancssOptions to allow passing in clean css options
rgba declarations are now always clamped e.g. rgba(-1,258,258, -1) becomes rgba(0, 255, 255, 0)
Fix possible issue with import reference not bringing in styles (may not be a bugfix, just a code tidy)
Fix some issues with urls() being prefixed twice and unquoted urls in mixins being processed each time they are called
Fixed error messages for undefined variables in javascript evaluation
Fixed line/column numbers from math errors