[$] 4.15 Merge window part 1

When he released 4.14, Linus Torvaldswarned that the 4.15 merge window might be shorter than usual due to the USThanksgiving holiday. Subsystem maintainers would appear to have heardhim; as of this writing, over 8,800 non-merge changesets have been pulledinto the mainline since the opening of the 4.15 merge window. Read on fora summary of the most interesting changes found in that first set ofpatches.