Minor include sorting changes

Minor include sorting changes

Make the include sorter sort files based on the basename of the file,
i.e., not including the extension into the string sort.  This fixes an
unintuitive behavior that causes changes in the include order if a
'-' <-> '_' replacement is done for a file name (because '-' and '_' are
on different sides of '.' in ASCII).

Change-Id: Icd4bf58b0d60178e33f6840f24adb1e4108fb92a