Add a new label placer function label_placer_middle() (#24, @jamarav).
The vendored testthat/catch code now uses a constant value for the stack size rather than relying on SIGSTKSZ. See: https://github.com/r-lib/testthat/issues/1373
clip_lines(), less likely to experience numerical instabilities.Added isolines_grob() for drawing labeled isolines via the grid graphics system. A companion function isobands_grob() is provided for convenience.
Numerous minor fixes and improvements.
First public release.