Lots of backwards incompatible changes to improve the experience

This adds a sample crypttab file for users to deploy to /etc/crypttab.

This version changes the syntax of the crypttab file. Previously, the
syntax was

  <mapper_name>  <device_path>  <key_path>

The mapper name is now inferred from the device path (replacing all `/`
with `_` so `/dev/sda1` becomes `_dev_sda1` for example). The new syntax
is:

  <crypt_device>   <key_path>   <mount_path>

Note that the mount path is now included. Previously it was expected
that the user would include the mapper path in their fstab file so a
subsequent `mount -a` would mount it once decrypted. This has all kinds
of service start order problems. Now crypttab handles mounting and
unmouting, so the mount path is part of the config file.

This also now makes `lsof` and optional program so stopping mount still
works if lsof is not installed.

1 files changed, 4 insertions, 0 deletions

diff --git a/crypttab.example b/crypttab.example
new file mode 100644
index 0000000..07b2586
--- /dev/null
+++ b/crypttab.example
@@ -0,0 +1,4 @@
+#
+# /etc/crypttab: Crypttab file system information
+#
+# <crypt_device>   <key_path>   <mount_path>