Remove devKerning

Dev kerning is not supported by any scalers. This is
mostly removed. The remaining fields fRsbDelta and
fLsbDelta are kept to keep Android compiling.

Change-Id: If1a9ee9bb599d4e1bdf4b3751ac0c65246350809
Reviewed-on: https://skia-review.googlesource.com/124921
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Herb Derby <herb@google.com>
23 files changed