Align free regions used for partition growing calculations.
Align free regions used for partition growing calculations.

Using unaligned free regions only introduces unusable sectors when
calculating growth amounts for aligned partitions.

Resolves: rhbz#1083687

vpodzime/blivet,AdamWill/blivet,dwlehman/blivet,dwlehman/blivet,rvykydal/blivet,vojtechtrefny/blivet,rhinstaller/blivet,rhinstaller/blivet,rvykydal/blivet,vpodzime/blivet,jkonecny12/blivet,AdamWill/blivet,jkonecny12/blivet,vojtechtrefny/blivet