- Remove test of raw temp for thermistor 0 when using MAX6675
- Longer `raw_temp_value` array for `TEMP_SENSOR_1_AS_REDUNDANT`

I've updated the minimum values from the LCD.
It has been a while that i want to at least fix this.
I have an inductive probe and often i need to set my zOffset to something lower than 0.5.
With the current implementation, the default LCD value is set to 0.5 for some reason.
On my case i need to be able to set it down to 0.0 as my inductive probe can be lower than 0.5.
Before with the LCD we couldn't change this value below 0.5. We had to flash the firmware every time which was painful.
Now we are able to change this value down to 0.0 if needed.
I've also changed the minimum value for Z min acceleration.
In the default configuration it's set to 25 but on the LCD the minimum was 100 which is not coherent.
I've changes the minimum to 10. On this axis, depending on the mechanics/motor drivers we might require very low acceleration, so i guess 10 is somehow realistic.

- Get rid of unused temp states in the ISR, resulting in more frequent
temperature reading with fewer sensors
- Shrink code slightly in min/max testing

- Address issue #1669
- Remove the TOPO_ORIGIN configuration setting

- Patch up macros in stepper.cpp

- Address #1262 by leaving values as set
- Rename `add_homing` to `home_offset`

- `Conditionals.h` is included twice, setting LCD values the first time

- Base tests on all thermistors/thermocouples, not just heater 0

- Prefetch values used more than once

- Use named axis indexes, `X_AXIS` etc.
- Replace `block.steps_A` with block.steps[A]`
- Replace `A_segment_time` with `segment_time[A]`
- Add `A_AXIS`, `B_AXIS` for `COREXY` axes
- Conditional compile based on `EXTRUDERS`
- Add BLOCK_MOD macro for planner block indexes
- Apply coding standards to `planner.h` and `planner.cpp`
- Small optimizations of planner code
- Update `stepper.cpp` for new `block` struct
- Replace `memcpy` with loops, let the compiler unroll them
- Make `movesplanned` into an inline function

by updating 'encoderPosition' in END_MENU() line 1.

- Addressing #1625

- Not sure why these are showing as all new

- Add `Conditionals.h` with calculated configuration values
- Add `SanityCheck.h` with checks for configuration errors
- Remove equivalent code from all configurations
- Move error checks from some sources to `SanityCheck.h` also
- Fix initialization of count_direction in stepper.cpp

by shifting things some pixels around

In the new method we pass the character that should be used for
selected state, not the character to print always.

- Pass selected state directly to lcd_implementation_mark_as_selected
- Rename sel function parameter
- Include a minor fix for SdBaseFile.h

When one hit "Stop Print" option in LCD menu, the command buffer was not
cleared. The printer keep moving until the buffer has been emptied.
Actually I could not clear the command buffer as well.. I don't know
why, it doesnt work as expected.
I need to implement a routine inside Stepper ISR to handle such
situation.

in ultralcd_implementation_hitachi_HD44780.h lcd_print( about array index.

Saves one addition.
Needs one pointer on the stack.

Don't know if this is a go trade.

Tried to make it a little intelligent.

Shoot in the dark.

Got:
Marlin_main.cpp:2567: warning: unused variable 'codepos'

Needs revision.
Don't now how this should look like.

Got:
Marlin_main.cpp:1689: warning: 'codenum' may be used uninitialized in this function

And indeed codenum is undefined when no parameter is given.

got:
Marlin_main.cpp:387: warning: 'delta' defined but not used

Compiles cleaner when definition is removed.

got:
ultralcd.cpp:408: warning: 'void lcd_autostart_sd()' defined but not used

Got:
ultralcd.cpp:64: warning: 'void lcd_control_retract_menu()' declared 'static' but never defined

While bunting an other bug I stumbled across:
ultralcd.cpp:1250: warning: comparison between signed and unsigned
integer expressions
Changed to the type of lcd_next_update_millis.

Users hat to press kill-button for unexpexted lon times.
See #1593