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* major internal refactoring
* use new "depends" key in repodata
* uses pycosat to solve constraints more efficiently
* add hard-linking on Windows
* fixed linking across filesystems (issue 103)
* add conda remove --features option
* added more tests, in particular for new dependency resolver
* add internal DSL to perform install actions
* add package size to download preview
* add conda install --force and --no-deps options
* fixed conda help command
* add conda remove --all option for removing entire environment
* fixed source activate on systems where sourcing a gives "bash" as $0
* add information about installed versions to conda search command
* removed known "locations"
* add output about installed packages when update and install do nothing
* changed default when prompted for y/n in CLI to yes