clubSandwich 0.3.0
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* Added methods for ivreg objects.
* Added methods for mlm objects.
* Updated residuals_CS.plm to account for changes in plm 1.6-6.

clubSandwich 0.2.3
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* Updated methods for plm objects to account for changes in plm 1.6-6.
* Added methods for glm objects.
* Added documentation of "type" options in vcovCR().
* Added examples for all vcovCR() methods.
* Provide facility to cluster at higher level than highest random effects for lme and gls objects.
* Added impute_covariance_matrix() utility function for multivariate meta-analysis.

clubSandwich 0.2.2
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* Added bread() methods for all supported model classes.
* vcovCR() is now calculated using bread(), and carries attributes for bread, est_mat, and adjustment matrices.
* vcovCR() gains a 'form' argument to obtain just the meat of the sandwich, or to use a user-specified bread matrix. 
* Refactored internal functions for degrees of freedom calculation to improve speed and memory usage.
* Bug fixes:
  - updated nobs.plm method to handle first-differenced models
  

clubSandwich 0.2.1
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* First version released on CRAN.