Merge pull request #1358 from samoht/master

Fix the internal solver to work decently again.
Fix handling of ftp urls
Merge pull request #1360 from AltGr/fix-ftp

Fix handling of ftp urls
Remove the complex and unused `opam config {asm,byte}{comp,link}`
Remove the complex and unused `opam config -I` command
Simplify the libraries and syntax fields

Show them on `opam show`
Simplify the structure of .config file

No more subsections, only a list of variables.
Update the dev manual
Update the tests to not use the `opam config <weirdthings>` anymore

No, OPAM is not a build system.
Add a script to add library/syntax from ocamlfind to OPAM metadata

To use it:

$ opam-admin lib --infer <pkg>

Currently, just look at the list of uninstall targets. Could be completed to look into the archive directly.