collapse version 2.1.6

• The repo has moved to fastverse/collapse and the website to fastverse.org/collapse---for better visibility and maintenance. Appropriate redirects from the old repo/site have been implemented.
  Selected people now have access to the repo through the organization account and may respond to issues or submit fixes.

• Added new AI-generated interactive/chattable DeepWiki documentation.

• collapse now treats -0 and 0 as the same value in hash functions (funique(), group(), fmatch(), fndistinct(), fmode(), and all higher-level derivatives). This is implemented by adding a value of 0.0 to double values before hashing them, and has a small (~3%) performance penalty when hashing doubles. It is implemented in synch with an equivalent change in Rcpp. Thanks @mayer79 for reporting and helping with benchmarking the performance implications (#648).

• Fixed a bug in pivot(..., how = "wider", FUN = "sum") (using internal sum function) when columns to aggregate were integer typed. Thanks @ummel (#803).

• Fixed a bug in roworderv(..., neworder = indices), which segfaulted if indices were out of range. Thanks @JanMarvin (#807).

• Faster installation from source thanks to the #include <Rcpp/Lighter> option in Rcpp which loads only part of the header files. Thanks @eddelbuettel for the hint.

• Consistency with internal updates to data.table. Thanks @aitap (#809, Rdatatable/data.table#7497).