CRAN version 0.2.4

Major changes

• plot_network() no longer depends on the 'visNetwork' package; the interactive network visualisation is now rendered with a bundled 'D3'-based JavaScript skeleton shipped in inst/js (see #118)
• That new network plot includes additional interactive capabilities, like function selection and highlighting.

Minor changes

• Improve diagnosis of wrong ctags version of MacOS (#115; thanks for @mcol)