intel disk system: restrict maximum supported size.

* The MBR can only address 2^32 blocks.
* This prevents you from initializing a disk larger than 2TB with a block
  size of 512 bytes.
gpt: do not advertize the partition as read-only.
Renamed the button "Desktop (Live-CD)" to "Boot to Desktop".

Fixes part of #9399
Symlink Installer to the Desktop only on read-only medium.

Fixes part of #9399
Renamed ReadOnlyBootPrompt to FirstBootPrompt.

The previous name is no longer applicable, as *BootPrompt is now launched on
the first boot of writable medium (e.g., USB thumb drive and hard drives).
Fixes part of #9399.

Notes:
 * BootPrompt.rdef may have lost its history.
 * The renaming was done with the following command:
   git mv src/apps/readonlybootprompt src/apps/firstbootprompt
Relocate the catkeys for FirstBootPrompt.

Edits will follow.

Fixes part of #9399.
Manually updated the application signature in catkeys.

The last part of fixing #9399.

Note: Hopefully this is 'OK'. `jam -q catkeys` and `jam -q catalogs` ran
without issue. Running FirstBootPrompt managed to use up the compiled catalogs.
Lost the "EFI" in front of "GUID Partition Map" name.

* This is how other systems refer to it as well, and is shorter, too.
DriveSetup: improved error reporting when deleting a partition.
gpt: the disk system now correctly maintains free space.

* Ie. the BPartitioningInfo should now be correctly filled.