ete3 merge

[jhcepas]

Once all other issues are finish, specially the one regarding the structure of files, we will need to merge the repo into a new ete3 branch.

@unode has some experience on this and I (@jhcepas) can also help

[dpliakos]

Hello!! It's been a bit of a time :)
We could do it using git submodules, in that case a "treematcher" directory is added
to the repo's root directory (path can be modified). The new directory is a reference to another repository whitch can be pulled, pushed,
rebased etc

Pros:

• Keep treating treematcher as both complete and indipendent repo (history and github workflow for developement) and use git submodule COMMAND to handle it as submodule while using ete repo.
  COMMAND can be update, merge etc

Cons:

• treematcher structure has to change so can be called as python -m ete3.treematcher .
• documentation and tests has to be to a ete's corresponding directories.

Another approach with same results is the Git subtree merging. I do not quite understand the process to explain it.

pros and cons I believe are the same for both options, but they differ at the process.