MFH: r364219

- Fix build with clang (hardcoded linking with libstdc++)
- Respect CXXFLAGS during build
- Add staging support
- Convert to USES=libtool, new options framework

Approved by:	portmgr (erwin)
MFH: r364302

- Fix build with clang (functions not returing value)
- Respect CFLAGS during build
- Add staging support
- Switch to PLIST_FILES
- Rename patches to current standards

Approved by:	portmgr (erwin)
Make sysutils/pstree operable in jailed environment.

(cherry picked from commit 0aa00da618ffa2bc5b4c4f8b89be22b9df2e9936)
Fixed replacement of $(PGBOUNCER_RUNDIR) in files/pgbouncer.in
Revert "Define and use "our_gid" variable."