New `pattern_linewidth` aesthetic?

[trevorld]

• {ggplot2} is renaming the size aesthetic to linewidth when referring to line widths
• Should {ggpattern} rename the pattern_size aesthetic to pattern_linewidth when referring to pattern line widths to match the above change?
• Obviously keep support for pattern_size for backwards compatibility...

[trevorld]

Perhaps easier if we first support new linewidth parameter in {gridpattern}: trevorld/gridpattern#57

[trevorld]

• Development version of {gridpattern} can now handle either using pattern_linewidth or pattern_size (and makes both available to custom patterns).
• Looking at what {ggplot2} did it seems keeping backwards compatibility for pattern_size would be a "non-trivial" enterprise and currently there aren't any known patterns that need both a pattern_size and pattern_linewidth aesthetic... Leaning towards not adding a new pattern_linewidth aesthetic for now but would be open to backwards-compatible pull requests that implement this...