tests/blacklists/linux-vfat

histedit: conditionalize the imports of 'fcntl' and 'termios'

The recent import of chistedit in c36175456350 made Windows sad.  I'm not sure
if there's other stuff that needs to be done here (e.g. change the default
interface), but this makes the tests run again.

It would have been nicer if the error message indicated these modules were the
problem, but instead it said "*** failed to import extension histedit: No module
named histedit".  I'm not sure if there's anything we can do about that.

# invalid filenames
test-add.t
test-init.t
test-clone.t
test-contrib.t
test-hgweb-raw.t
test-walk.t

# no sockets or fifos
test-hup.t

# no hardlinks
test-hardlinks.t
test-relink.t

# exec bit problems
test-convert-bzr-114.t
test-convert-bzr-directories.t
test-convert-bzr-merges.t
test-convert-bzr-treeroot.t
test-convert-darcs.t
test-merge-tools.t

# debugstate exec bit false positives
test-dirstate.t
test-filebranch.t
test-merge-remove.t