libc: Don't filter out sigsetjmp from libc-gen

Issue #1085
tool: test result output of amtterm reset

"amtterm reset" returns 0 as exitcode even if the reset command failed.
So check explicitly the output of the command to detect the error case.
libc_fs: Make plugin thread safe

Issue #1090
rump: Add panic message
vbox: Increase quota for rump_fs in auto test
run: enable virtualbox auto test for nightly runs

With #1090 fixed the test should succeed now.
precondition for "Simplify Framebuffer::Session interface"

scout: include scout/platform.h for new operator
squash me: "run: enable virtualbox auto test for nightly runs"