MFH: r406516

devel/cargo: update to 0.7.0 (release) and cleanup

• Compress :registry with xz(1) to save a few megabytes
• Add BOOTSTRAP option to build with already installed Cargo
• Generate distfiles with BOOTSTRAP=off for extra deps
• Require recent lang/rust to build (older versions not tested)
• Drop cargo-nightly and rust-nightly hacks. The latter is still supported via RUST_PORT=lang/rust-nightly in environment, make.conf, Makefile.local
• Drop MAKE_JOBS_UNSAFE, builds fine with MAKE_JOBS_NUMBER=32
• Drop _GH0 suffix from non-GitHub distfile
• Don't use OpenSSL port on 11.0-CURRENT (no RPATH in bootstrap)
• Don't install duplicate licenses under DOCSDIR
• Don't depend on lang/python2 when only lang/python27 is used
• Simplify manpage directory substitution
• Fix LICENSE_FILE when used with LICENSE_COMB != single
• Fix gen-registry target when WRKDIRPREFIX == MAKEOBJDIRPREFIX
• Cleanup gen-registry target
• Respect PREFIX != /usr/local
• Prepare CARGO_BOOT_SIG for i386 and DragonFly
• Apply minor style

PR: 205529
Approved by: maintainer timeout (1 month)
Approved by: ports-secteam (feld)
Differential Revision: https://reviews.freebsd.org/D4562