extend - replace elements multiple times in a path
Add exact syntax for extend
support for deep but exact extend
Alpha update
Implement syntax in gh #1185 for @import options.  Implement multiple & less.

First step in implementing syntax for @import options, proposed in
https://github.com/cloudhead/less.js/issues/1185#issuecomment-13710620
(steps (1) and (2)).

I've implemented the 'multiple' and 'less' options.  One could trivially
add 'once' and 'css' options as well, if there was need.  Proposed
"silent" and "inline" options are deferred for future work.

I left the existing "@import-multiple" and "@import-once" syntax in place,
although the proposal is for this to be deprecated once the new option
syntax is in place.
Change import options to require '('
remove short lived `@import-once`  in favour of `@import` (default is once) and `@import (multiple)` for multiple
don't remove duplicate comments, fixes #1067
error when property is used in root. Fixes #442
remove shallow/deep options & tidy up part 1
refactor extend visitor to be more readable and maintainable
refactor mixin call arguments into a seperate function
correct bad test txt
Fix default variables containing comma when semi-colon seperated mixin definition. Fixes #1211
fix regression: mixin guards compare units correctly
* "Added a -depends switch which outputs a dependency line suitable for a makefile" (10696d9c11afccd7fb4dadd92985b5166c66f6f2)
* Added a synonym flag "-M" to "-depends" to match syntax of other compilers.
* Added support for recursive dependencies.
* Fixed some issues with path calculation when dependencies and recursive dependencies.

lukeapage - removed the actual writing of dependency lines ready for re-implementation
Add implementation of dependency tree
Allow multiple extends for more declarative multiple inheritance
Alpha release
fix, less with compression (-x) was unable to parse auto\9