Revert "Get rid of the planner"

This reverts commit c4a47a7d60b53c9b2e2ffb874afaf733d43123aa.
Add a travis.yml to test a build.
Mac support in travis.yml
Clone a bit deeper, so we get a tag to describe
Check return values of malloc/realloc in zip_read

Signed-off-by: Anton Lundin <glance@acc.umu.se>
Revert "Keep track of the minimum Depth / time on the planner."

This reverts commit 9a497b1cb0f38e8a7e04e29543da5241a38d2195.
Real fixup

Fixes: #358
WIP drop_stone_mode