sysutils/fusefs-sshfs: Improve FreeBSD support

• include posix_openpt() usage patch
• add workaround for readdir() issue: #211
• fix few warnings
• Add DOCS option
• remove gettext dep

Upstream patches:
https://github.com/libfuse/sshfs/pull/212
https://github.com/libfuse/sshfs/issues/211

PR: 246325
Submitted by: rozhuk.im@gmail.com