DietPi-Drive_Manager | Support ecryptfs mounts

[MichaIng]

Creating a feature request:

• Thanks @johnvick for reporting this.

Is your feature request related to a problem? Please describe:

• ecryptfs mount type (encrypted folder) is not yet supported and preserved, when opening dietpi-drive_manager.

Describe the solution you'd like:

• Adding feature to add an encrypted drive.
• Check/Preserve existing ecryptfs mounts.

Additional info:

• https://dietpi.com/phpbb/viewtopic.php?f=11&t=4803
• eCryptfs is a native Linux filesystem. The kernel module component of eCryptfs is part of the Linux kernel since 2.6.19.
  Should be possible to check for this kernel module and only offer the feature, if it is present.
• df => /home/john/crypt 29254192 16431072 12806736 57% /home/john/crypt
  Hmm, need to check if there is a better output to identify these mounts, as an identifying string is missing :?. Currently, as the "mount source" has no UUID, drive_manager just identifies it as network drive (thus should show it in the list), which need to be identified and added to fstab separately.
  I will do some research about it.

[MichaIng]

PR up: #2729

• No full support (handling these mounts), but at least the fstab entries are preserved.

[johnvick]

Thanks.