Fix busy detection of file systems inside Linux Software RAID (#712533)

On some distributions GParted doesn't detect when a file system is busy
and mounted when the partition is within a Linux Software RAID array.
Affected distributions include: Debian 6, Debian 7 and RHEL/CentOS 6.x.

This is because of a bug in libparted 2.3 and earlier.  It was fixed by
this change in libparted 2.4:
    http://git.savannah.gnu.org/cgit/parted.git/commit/?id=db52898c214310dab4ed84e6cb2f9ffc8c3aa502
    linux: also detect "in-use" dmraid and scsi-Nth (N>=16) partition

Ubuntu 13.10 with libparted 2.3 is not affected because it contains a
distribution specific patch to correct it.

Fix by using GParted's internal mounted partitions map, mount_info, to
determine if a partition is busy, in addition to using libparted's
ped_partition_is_busy().

Bug #712533 - Partitions not detected as busy inside Software RAID on
              some distros
Fix false busy detection of unusual case with Linux Software RAID (#712533)

In this unusual setup of having one Linux Software RAID array
partitioned and a second array not partitioned, /dev/md1p1 partition in
the first array is falsely reported as busy when the file system filling
the second array /dev/md2 is mounted.

  Partition   RAID                File System        Mount mount
  ---------   -----------------   ----------------   -----------
  /dev/sdb1   SWRAID /dev/md1
                     /dev/md1p1   ext4,Label=test1   (Unmounted)
  /dev/sdb2   SWRAID /dev/md2     ext4,Label=test2   /mnt/2

This again affects Debian 6, Debian 7 and RHEL/CentOS 6.x and is as a
result of the this bug fixed in libparted 2.4:
    http://git.savannah.gnu.org/cgit/parted.git/commit/?id=db52898c214310dab4ed84e6cb2f9ffc8c3aa502
    linux: also detect "in-use" dmraid and scsi-Nth (N>=16) partition

Fix by not using libparted's ped_partition_is_busy() to determine if a
normal or logical partition is busy.

Bug #712533 - Partitions not detected as busy inside Software RAID on
              some distros
Fix detection of busy status of extended partitions (#712533)

GParted doesn't report extended partitions as busy if it contains only
busy LVM2 PV or SWRAID logical partitions.  Libparted's
ped_partition_is_busy() only detects mounted file systems and swap space
as busy, not active LVM2 PVs or SWRAID members.  This is as of libparted
3.1 and earlier.

Fix by determining the busy status of an extended partition based solely
on the busy status of the logical partitions it contains.  This makes it
unnecessary to check for mounted DMRAID logical partitions or call
ped_partition_is_busy() for extended partitions.

Bug #712533 - Partitions not detected as busy inside Software RAID on
              some distros
Show SWRAID active/not active status in information dialog (#712533)

Bug #712533 - Partitions not detected as busy inside Software RAID on
              some distros
Remove multi-line comment compiler warning from PipeCapture.cc

Remove this compiler warning:
    PipeCapture.cc:56:2: warning: multi-line comment [-Wcomment]
      //      /\                                          /\        /\
      ^

added by commit:
    1b54123580aa668d3a2c391cce2d60c65a1668f9
    Enhance line discipline in PipeCapture::OnReadable() (#709276)