Log Message:
(math/R-sandwich) Updated 3.0.1 to 3.0.2

# sandwich 3.0-2

* Added new argument `aggregate = TRUE` to `meatPL()` which is thus inherited by
  `vcovPL()`. By default, this still yields the Driscoll & Kraay (1998) \ 
covariance
  matrix. When setting `aggregate = FALSE` the cross-sectional and cross-serial
  correlation is set to zero, yielding the "pure" panel Newey-West \ 
covariance
  matrix.

* Bug fix in `vcovCL(..., type = "HC2")` for `glm` objects or `lm` objects
  with weights. The code had erroneously assumed that the hat matrices were
  all symmetric (as in the `lm` case without weights). This is corrected now.
  (Detected and reported by Bixi Zhang.)

* Issue a warning in `vcovHC()` for HC2/HC3/HC4/HC4m/HC5 if any of the hat values
  are numerically equal to 1. This leads to numerically unstable covariances,
  in the most extreme case `NaN` because the associated residuals are equal to
  0 and divided by 0. (Suggested by Ding Peng and John Fox.)

* Speed improvement in `vcovBS.lm()`: For `"xy"` bootstrap, \ 
`.lm.fit()` rather than
  `lm.fit()` is used which is somewhat more efficient in some situations (suggested
  by Grant McDermott). For `"residual"` and wild bootstrap, the \ 
bootstrap by default
  still samples coefficients via QR decomposition in each iteration (`qrjoint = \ 
FALSE`)
  but may alternatively sample the dependent variable and then apply the QR
  decomposition jointly only once (`qrjoint = TRUE`). If the sample size (and the
  number of coefficients) is large, then `qrjoint = TRUE` may be significantly faster
  while requiring much more memory (proposed by Alexander Fischer).

* Enable passing score matrix (as computed by `estfun()`) directly to
  `bwAndrews()` and `bwNeweyWest()`. If this is used, the score matrix should
  either have a column `(Intercept)` or the `weights` argument should be set
  appropriately to identify the column pertaining to the intercept (if any).

* The vignettes have been tweaked so that they still "run" without \ 
technical errors
  when suggested packages (listed in the VignetteDepends) are not available. This is
  achieved by defining replacement functions that do not fail but lead to partially
  non-sensical output. A warning is added in the vignettes if any of the replacements
  is used.