give include comments the once over

In preparation for upcoming changes to bookmaker
which validate more include contents, revise
generated files in include/core to fix various
errors.

Fixes include:
- references in comments to other Skia interface elements
- @param names agree with function declarations
- spelling typos
- generic references (e.g. 'x' in place of 'x-axis')
- lines longer than 100 columns

The fix to SkPath::rCubicTo triggered a parallel
fix to SkPath_Reference.bmh; other wed documentation
fixes will be in an upcoming CL.

TBR=reed@google.com

Docs-Preview: https://skia.org/?cl=166680
Bug: skia:
Change-Id: If734696dc64655f1cf40b121a180210c932b1d89
Reviewed-on: https://skia-review.googlesource.com/c/166680
Commit-Queue: Cary Clark <caryclark@skia.org>
Auto-Submit: Cary Clark <caryclark@skia.org>
Reviewed-by: Cary Clark <caryclark@skia.org>
18 files changed