[PATCH/RFC 0/3] Split fetch and merge logic

This series implements the split of the fetch and merge logic.

The first patch adds tests for the merge logic. It is very extensive and
expensive (in time), so I just post this to show that (almost) nothing
changes (although some part of if could be included). And the third
patch shows what changes.

Santi Béjar (3):
      t/t5515-fetch-merge-logic.sh: Added tests for the merge login in git-fetch
      git-fetch: Split fetch and merge logic
      t/t5515: fixes for the separate fetch and merge logic