Revert FreeBSD compatibility layer

Revert FreeBSD compatibility layer

Move those commits to the compat-freebsd branch instead of master branch
which is currently between release canditate and stable and this compat
layer will NOT go into 2.0-stable.

Revert "Fix rest of the code to support compat layer"
This reverts commit a440509044c2828bf6dbfb05e8d9d6d0277ce1a4.

Revert "Fix consumer to handle compat layer"
This reverts commit fbb2c21aac1386b7752f6254b2bd0bf001fa0ac1.

Revert "Multiple fix for FreeBSD compat layer"
This reverts commit bcc5eeb02fcad910c4de961b040351dad31b6f9f.

Revert "Add multiple FreeBSD compat layer"
This reverts commit d50813007e79158828e8ee6e1b5444950bc90847.

Revert "Add FreeBSD compat layer for splice and sync_file_range"
This reverts commit 826a02a292d2bd409be87ea96ba2fccbccee76b1.

Revert "Support XSI strerror_r in error.h"
This reverts commit e672cc585c3d67ee80278e29b538a3aed65df825.

Revert "Add FreeBSD compat layer for socket.h"
This reverts commit ef50a575de02a28aa158d7ba34b3d20ea329751a.

Revert "Fix FreeBSD support for rculfhash mmap"
This reverts commit e21193ea4abf7d93112b8ad3144ba11484d623c6.

Revert "Add FreeBSD compat layer for endian.h"
This reverts commit ae9d96fe577c198df432102cde69a28e82cccc1b.

Signed-off-by: David Goulet <dgoulet@efficios.com>