ccxcz

Remove `closefrom()` call which breaks user-provided command when it relies on inherited file descriptors. This is a regression introduced in commit 66e9868 which introduces `closefrom()` call closing all file descriptors...

./configure --bindir option is not respected

2

Installing opam-full from source puts binaries into `$prefix/bin` instead of the provided `$bindir`. When building `opam-full-2.4.1` I configured it with following options: ``` + ./configure '--prefix=/home/ccx/versions/opam.3df4741f0b1229a4304e20cb571acf8439c5e1de51fa2a40423488b3bc07d39a' \ --libdir=/home/ccx/versions/opam.3df4741f0b1229a4304e20cb571acf8439c5e1de51fa2a40423488b3bc07d39a/library.ocaml' \ --bindir=/home/ccx/versions/opam.3df4741f0b1229a4304e20cb571acf8439c5e1de51fa2a40423488b3bc07d39a/command'...