Warn user about useless of individual axis homing and DELTA kinematics

Update Japanese translation

Addressing #3743

Removes the DISABLE from HOST_KEEPALIVE

Idle during long arcs

Idle during long arcs
to prevent from watchdog resets during high segmented fast arcs.

Saves about 2669 bytes when deactivated. (About 1% for a AT2560, about __4%__ for a AT644!)

Add a forgotten condition

・Add new translation

Individual Axis Homing LCD menu items

Follow-up the PR #3719(Harmonize LCD comment section)

It update forgotten Configuration_DUAL.h.

Print an error on bad i2c request

Add REVERSE_ENCODER_DIRECTION option

Reference: https://github.com/MarlinFirmware/Marlin/pull/3713#issuecomment-218333678

Minor #warning fix for PrintCounter

Harmonize LCD comment section

Mention Z_PROBE_ALLEN_KEY in probe sanity checks

Use code_value_long for potentially large values

Addressing #3711

Update Japanese translation, etc

・Arrange the strings in unified order
・Remove "#ifdef DELTA_CALIBRATION_MENU" directive
・Adjust spacing

・Add new translation
・Add translation for 16 width ASCII LCD
・Change translation
・Revert translation from Japanese to English
・Fix typo

Fixed Makefile to work with Melzi2 boards on arduino-1.6.x

Fallthru in thermal runaway test when TRState changes

Fix dipping on DELTA robots during G29

- Addressing #3689, et. al.

Enclose #error strings with apostrophes in quotes

Cleanup and consolidate probe conditionals for clarity