Euler_Partition: build upon Number_Partition theory to get rid of temporary duplicates
Created originally on Bitbucket by bulwahn (Lukas Bulwahn)
Was already merged in Bitbucket before import, marked as merged by the import user
This commit refactors the Euler_Partition theory to depend on the basic Number_Partition theory and use those definitions and lemmas, instead of re-defining and re-proving the same in Euler_Partition. This refactoring is due to that Euler_Partition was developed before the Card_Number_Partition theory, but the basic Number_Partition theory was developed with the Card_Number_Partition theory and it fits (for the time being) much better to the Card_Number_Partition entry than to Euler_Partition.