igraph 2.1.4.9042

## vendor

- Update vendored sources to igraph/igraph@05d1867 (igraph#1825).

igraph 2.1.4.9041

## Chore

- Results from main.

- Results from check with new arpack.

## Documentation

- Document return value of `make_clusters()` (igraph#1794).

igraph 2.1.4.9040

## Documentation

- Add author links (igraph#1821).

igraph 2.1.4.9039

## Bug fixes

- Remove string matrix support from biadjacency matrix functions (igraph#1540, igraph#1542, igraph#1803).

## Features

- `simple_cycles()` lists all simple cycles (igraph#1573, igraph#1580).

- Expose C version (igraph#1208, igraph#1781).

## Chore

- Format with air.

## Documentation

- Fix style (igraph#1819).

## Performance

- Accelerate check if an index sequence corresponds to the entire list of vertices (igraph#1427, igraph#1818).

igraph 2.1.4.9038

## Documentation

- Correct the description of the `weights` parameter of `hits_scores()`.

## Refactoring

- Adapt to `cut.prob`'s new handling of NULL in the C core (igraph#1570, igraph#1602).

igraph 2.1.4.9037

## vendor

- Update vendored sources to igraph/igraph@09f6f25 (igraph#1814).

- Update vendored sources to igraph/igraph@d48a25b (igraph#1813).

igraph 2.1.4.9036

## Features

- Expose `is_complete()`, `is_clique()` and `is_ivs()` (igraph#1316, igraph#1388, igraph#1581).

## vendor

- Update vendored sources to igraph/igraph@a68d7ca (igraph#1811).

igraph 2.1.4.9035

## vendor

- Update vendored sources to igraph/igraph@01b15eb (igraph#1808).

- Update vendored sources to igraph/igraph@8d5db4d (igraph#1807).

- Update vendored sources to igraph/igraph@6c5b349 (igraph#1806).

igraph 2.1.4.9034

## Bug fixes

- Removed redundant inheritParams call (igraph#1802).

- Loops not plotted on canvas (igraph#1799, igraph#1800).

- Load the Matrix package before coercing to a sparse matrix.

- `NA` replacement for labels in plots and arrow mode (igraph#1796, igraph#1797).

## Chore

- Results from revdepcheck.

## Testing

- Added more weight tests to `graph_from_biadjacency_matrix()` (igraph#1544, igraph#1804).

igraph 2.1.4.9033

## Features

- Add relative size scaling to vertices in plots (@gvegayon, igraph#172).

## Chore

- Render docs.

- Updated results.

## Documentation

- Better describe output of `all_shortest_paths()` (igraph#1029, igraph#1778).