Hanada-san's cosmetic changes
port minor patches to the backend into part-1 patch
Merge branch 'custom_scan' into ctidscan

Conflicts:
	src/include/optimizer/cost.h
remove typo fix
Merge branch 'ctidscan' into postgres_fdw

Conflicts:
	src/backend/nodes/bitmapset.c
	src/include/nodes/bitmapset.h
fix tabbing
Merge branch 'custom_scan' into ctidscan
Merge branch 'ctidscan' into postgres_fdw