Fix cmdliner dependency.

Update the dependency to GitHub since the current source no longer
exists.
Merge pull request #971 from cmeiklejohn/csm-resolve-cmdliner

Fix cmdliner dependency.
Fix archives that have no base extension: treat them as tar as 1.0 did

Closes #972
Really compute transitive dependencies in opam_mk_repo (Close: #976).
Merge pull request #975 from avsm/repair-blank-extension-archives

Fix archives that have no base extension: treat them as tar as 1.0 did
Use 3.12 M.() to shorten the change.
Fix bugs in the way we visit all the dependencies graph for get_transitive_dependencies.
Fix typo in get_transitive_dependencies.
Update CONTRIBUTING

Correct URL in CONTRIBUTING
Clean more files
Revert "Fix cmdliner dependency."

This reverts commit 0230460d58504d204b4dbc801673034d2ca684e8.
Fix and improve the travis scripts
Merge pull request #990 from samoht/master

various minor fixes
Merge pull request #977 from gildor478/master

Really compute transitive dependencies in opam_mk_repo (Close: #976).
Install cohttp before trying to compile opam-rt in the Travis CI scripts
Update CHANGES
Bump version number of trunk
[travis] install cmdliner to compile opam-rt
[travis] add the right dependencies to compile opam-rt
[travis] use the system libraries to compile opam-rt