Enable %age complete display from e2fsck command (#697662)

Enable the text progress bar and percentage complete from the e2fsck
command.  Looks like:

    # e2fsck -f -y -v -C 0 /dev/sda8
    e2fsck 1.41.12 (17-May-2010)
    Pass 1: Checking inodes, blocks, and sizes
    Pass 2: Checking directory structure
    test8: |=========================================               / 73.6%

Note that e2fsck deliberately brackets the progress bar with control-A
and control-B characters when it detects that it is not being run from a
terminal so that logsave(8) can exclude the progress bar from being
written to a log file.  As GParted doesn't run e2fsck via a pty it
receives these control characters.  Ignore them.

References:
Change e2fsck to bracket its progress bar output with ctrl-A and ctrl-B
http://git.kernel.org/cgit/fs/ext2/e2fsprogs.git/commit/?id=bc34d6be65cb93a65451ad209cfea2f98b03fd22

Don't print ^A and ^B chars when e2fsck is talking directly to a tty
http://git.kernel.org/cgit/fs/ext2/e2fsprogs.git/commit/?id=54a31a3b2e432c124aa03442f2983c4f4d4a974c

Closes Bug #697662 - Do not hide the progress of the tools used