Introduced lcd_strlen() and lcd_strlen_P().
Replaced the old functions where necessary.
Reworked language_ru.h.

Speeded up test for zero length string in cardreader.cpp

- Also partial cleanup of Marlin_main.cpp with a smidgen of Doxygen.

sp=space-padded, similar to: ns=no-sign

No matter what LANGUAGE_CHOICE was set to it would always take the en branch.
I revamped it a bit to use a macro to create the language include file name. This required a slight tweak to the RU declaration since it's special-cased in a couple places in code.

This is an attempt to pull my changes from #1222 over.

Tested for SAV MKI and SAV 3D LCD on lewihe.

sp=space-padded, similar to: ns=no-sign

Breaking up languages.h makes it easier to translate. Using language
codes makes it easier to select a language and sets the naming standard.

Changes to support displaying the real-time filament width and the
volume factor on a 20x4 LCD.  The data is displayed on the 4th line.
First the status message is displayed for 5 seconds, and then the
filament data is displayed.  The status message can be seen by
re-selecting the info screen in the menu.

When using LCD_I2C_TYPE_PCF8575T (like Sainsmart I2C), the backlight
won't come on; the incorrect ifdef blocks the evocation of the backlight
functions.

I added #define for LCD_FEEDBACK_FREQUENCY_HZ and
LCD_FEEDBACK_FREQUENCY_DURATION_MS  which is used to alter the default
buzzer sound.

When selecting Panelolu2 in configuration.h:
- it automatically sets the correct ENCODER_PULSES_PER_STEP and
ENCODER_STEPS_PER_MENU_ITEM.
- if LCD_USE_I2C_BUZZER is defined it will also set the default
LCD_FEEDBACK_FREQUENCY_HZ and LCD_FEEDBACK_FREQUENCY_DURATION_MS

When selecting the sanguinololu 1284p the following is true:
- its now enables  LARGE_FLASH
- It enables the gcode M300 when the panelolu2 LCD_USE_I2C_BUZZER is
defined

Included support for BT dongle on AT90USB boards.
Added LCD Shift Register LCD control
Included support for RepRap Clone Wars project board (SAV MKI).

Hopefully fixed viky button handling without braking other boards

Bug introduced in version 6beb42cdf6.
Robert did a good job of simplifying but messed up this chunk of code.

Looking at working version: 839bef6d5d
it seems there is no case where encrot3 should be defined as 2
because if ULTICONTROLLER is defined then NEWPANEL is also defined.

Diffed and merged, preserving my updates

The I2C LCD status indicators now indicate when the hotends or bed are
turned on at all (rather than just when they are in their heating phase)

Add new 'callback' edit-menu types that call a function after the edit is done. Use this to display and edit Ki and Kd correctly (removing the scaling first and reapplying it after). Also use it to reset maximum stepwise acceleration rates, after updating mm/s^2 rates via menus. (Previously, changes did nothing to affect planner unless saved back to EEPROM, and the machine reset).

Add calls to updatePID() so that PID loop uses updated values whether set by gcode (it already did this), or by restoring defaults, or loading from EEPROM (it didn't do those last two). Similarly, update the maximum step/s^2 accel rates when the mm/s^2 values are changed - whether by menu edits, restore defaults, or EEPROM read.

Refactor the acceleration rate update logic, and the PID scaling logic, into new functions that can be called from wherever, including the callbacks.

Add menu items to allow the z jerk and e jerk to be viewed/edited in the Control->Motion menu, as per xy jerk.

Conflicts:
	Marlin/language.h

The new version of the library means that PANELOLU no longer needs to be
defined in LiquidTWI.h (the library file can be used as is) and the new
version of the library also enables the buzzer on the Panucatt VIKI
panel.

This change also handles the case where the pause/stop/restart button on
the VIKI is not used. Make LCD I2C buzz sound the same as the normal
buzz (300ms is too long for quick feedback).

Refactor configuration to try to make items clearer (what defines a
panel vs what is user changeable).

This includes refactoring the buttons code to remove a large amount of
non-pin dependent duplication from pins.h.

Removed incorrect LiquidCrystal_I2C Library

Fix to a bug that I just introduced - sorry. Forgot about offset of string length.

Use all available characters in narrow LCDs < 20 characters.

Fix to a minor bug with hardcoded LCD_WIDTH that draws edited values outside of the 16 characters width LCDs.