moder (development version)

New functions frequency_grid_df() and frequency_grid_plot() to analyze and visualize possible frequency distributions given missing values.
Fixed a bug in mode_count_range() that displayed a maximum of 0 for certain kinds of input.
In mode_possible_min() and mode_possible_max(), the multiple argument was renamed to accept for greater consistency with mode_first() and other functions.
mode_possible_max() no longer returns NA if the number of NAs in the input is equal to or higher than the number of "empty slots" (i.e., the hypothetical non-NA values that would have to be present in x in order for all of its unique values to be equally frequent). After all, it is possible for all unique values to be "filled up" by NAs so that they are themselves modes.

moder 0.2.1

Patch for CRAN submission.

mode_count() and all other metadata functions now have a max_unique argument, allowing users to encode knowledge about missing values in the analysis.
mode_single() now has an accept argument for opting into a less strict check for a single mode, in analogy to mode_first().
mode_first() had its first_known argument renamed to accept for consistency with mode_single().
Further improvements to the documentation, including vignettes.

New functions for modal metadata:
- mode_is_trivial()
- mode_frequency()
- mode_count_range()
- mode_frequency_range()
New vignettes on missing values, metadata, and performance.
Many bugfixes and other improvements.