Revert "Improvements in downloaded Excel WIP."

This reverts commit 6e72cf1cb424609f1fedc44a1d9bfe3240fe3f91.
Revert "Revert "Improvements in downloaded Excel WIP.""

This reverts commit b983dfba83f82ac2a4cf9158388fc22ff7752401.
Revert "Added pythonhelpers submodule."

This reverts commit 0f50b93b362058a821e4d816c90645b6106339a7.