Fix undefined DELTA_PROBEABLE_RADIUS for UBL_DELTA

* Fix M48 for Delta's  There was a scope issue: DELTA_PROBEABLE_RADIUS wasn't getting defined.

* Check if the specified G29 command requires homing

Things should be pretty stable for a while.   
But it wouldn't surprise me if the Delta people have a need for a few special commands.

Since we already used 'T' for `G29` Topology Report in the past, and since 'T' is available…

It was missing MSG_FILAMENT_CHANGE_HEAT_2 and MSG_FILAMENT_CHANGE_HEATING_2

* UBL_DELTA post merge cleanup:
   fix fade_height, lost during some previous merge
   fix float cx,cy which are not const
   move repeated z_cxcy calc line inside loop
   style fixes and comment fixes/alignment

* Update ubl_motion.cpp

remove unnecessary parentheses

* Update Conditionals_post.h

Change name of define to more accurate meaning:
UBL_GRANULAR_SEGMENTATION_FOR_CARTESIAN
which is not and should not be the default for cartesians with UBL.

Also clean up ubl_motion.cpp debug info and fix declaration of cx & cy

Updated Basque translation with new strings.

Update the gMax files to display better with Proportional Fonts

Adding the capability to specify ahead of time how much of the validation pattern to print made it so by default G26 only did one circle and no connecting lines.

It is more natural for the unsophisticated user to just do the entire mesh (bed).   We default the repetition count to GRID_MAX_POINTS+1 to insure we get every last one of them!

UltiPanel was enabled, but technically, it is a REPRAP_DISCOUNT_SMART_CONTROLLER
Either configuration works on the machine.  But we want it 'Right'.

Setup the Proportional Font spacing so columns line up nicer on PronterFace and Repetier Host.

Extra closing curly bracket terminates while loop early if PRINTER_EVENT_LEDS defined

UBL on Delta's....     Should be close!    Should not affect any Cartesian printer.

- allow H code value to override probing height
- minor cleanups

- Split M421 into separate versions for bilinear and ubl
- Fix minor issue in G26

* M421 Mesh Point Offset and misc. UBL clean up

Allow M421 to accept an offset as well as absolute value for a specified
mesh point.
And misc. UBL clean up to reduce redundent code.

* Better error checking for M421

* Fix M421 Y index bug

I just noticed....  We've had a Y index bug for who knows how long?

- update example configs

- Allows for specifying number of points to print/validate, using 'R' code like with G29 P4 Rx
- Moved the code for Random to 'M' so we could be consistent with G29 P4
- G26 instructions indenting/cleanup

- Fix bug in ubl_line_to_destination
- Improve/fix output of some ubl.h functions

    /**
     * UBL System submenu
     *
     *  Prepare
     * - Unified Bed Leveling
     *   - Activate UBL
     *   - Deactivate UBL
     *   - Mesh Storage
     *       Memory Slot:
     *       Load Bed Mesh
     *       Save Bed Mesh
     *   - Output Map
     *       Map Type:
     *       Output Bed Mesh Host / Output Bed Mesh CSV
     *   - UBL Tools
     *     - Build Mesh
     *         Build PLA Mesh
     *         Build ABS Mesh
     *       - Build Custom Mesh
     *           Hotend Temp:
     *           Bed Temp:
     *           Build Custom Mesh
     *         Info Screen
     *       - Build Cold Mesh
     *       - Fill-in Mesh
     *           Fill-in Mesh
     *           Smart Fill-in
     *           Manual Fill-in
     *           Info Screen
     *         Continue Bed Mesh
     *         Invalidate All
     *         Invalidate Closest
     *     - Validate Mesh
     *         PLA Mesh Validation
     *         ABS Mesh Validation
     *       - Custom Mesh Validation
     *           Hotend Temp:
     *           Bed Temp:
     *           Validate Mesh
     *         Info Screen
     *     - Edit Mesh
     *         Fine Tune All
     *         Fine Tune Closest
     *       - Adjust Mesh Height
     *           Height Amount:
     *           Adjust Mesh Height
     *         Info Screen
     *     - Mesh Leveling
     *         3-Point Mesh Leveling
     *       - Grid Mesh Leveling
     *           Side points:
     *           Level Mesh
     *         Info Screen
     *   - Output UBL Info
     */