Add proper delay in stepper.cpp

removed function step_wait() from stepper.cpp because its used nowhere.

Issue #1385 describes a delay that the compiler is optimizing out and
this solution.

# Add: Example Configuration for Vellemann K8200 - based on new
BOARD_K8200 #1391

* K8200: new folder in example_configurations for Vellemann K8200 (3Drag
clone - should work with 3Drag http://reprap.org/wiki/3drag, too. Please
report)
* K8200/Configuration.h/Configuration_adv.h: updated manually with
parameters form genuine Vellemann Firmware "firmware_k8200_marlinv2"
based on the recent development branch

I tested the changes on my K8200 with 20x4-LCD and Arduino 1.0.5 for
Windows (SD library added to IDE manually) - everything works well

## Add: Board for Vellemann K8200 (derived from 3Drag)

* Boards.h: updated comment for board 3Drag - K8200 removed
* Boards.h: added `BOARD_K8200` with ID 78

* language.h.: machine name and firmware URL for new board

* pins.h: added `K8200` to any `#if` with `3Drag` and corresponding
comments

Show Custom M Code when entering M503

Update Boards.h for Vellemann K8200 - comment only

Remove hardcoded programmer option (-cwiring).

This reverts commit 935ee968a7.

Still not fine tuned but working.

When a melzi board and a full gfx are both selected, the build fails
blaming for some missing defines.

This is a fix for the issue: now my configuration works.

## Update Boards.h for Vellemann K8200 - comment only

* Boards.h: updated comment for board 3Drag - K8200 uses same board

This reverts commit 5333590ac2.

* K8200: new folder in example_configurations for Vellemann K8200 (3Drag
clone - should work with 3Drag too, please report)

* K8200/language.h: updated machine name and URL for K8200

* K8200/Configuration.h/Configuration_adv.h: updated manually with
parameters
form genuine Vellemann Firmware "firmware_k8200_marlinv2" based on the
recent development branch

* K8200/files by Vellemann: added folder with original files from
Vellemann homepage, since there is no GitHub fork you could link to by
them

I tested the changes on my K8200 with 20x4-LCD and Arduino 1.0.5 for
Windows - everything works well

Change default value of AVRDUDE_PROGRAMMER to 'wiring'.

Revert "Reduce PROGMEM warnings"

Update printrboard pin assignments

Backported from Printrbot branch, allows the fan to work correctly.

Revert "Move Sd library out into library"

Fixes #1361

Improvement - G29 Option for Not Retracting Servo

Rambo FAN_PIN documentation and servo support

Move Sd library out into library

fix avrdude upload in makefile

Update GCodes.md

Removed remaining angle brackets which are not displayed properly in Github-flavored Markdown.

Independent PID parameters for each extruder

Reduce PROGMEM warnings

Update GCodes.md

Sort Gcodes numerically, other minor formatting changes

G29 E was not retracting the probe on the last probe point when used with ABL grid. Corrected.

* Adds config parameter `PID_PARAMS_PER_EXTRUDER` - allows single PID
parameters to be used where this would be preferable (e.g. dual
identical extruders)
* When disabled, will use `float Kp, Ki, Kd, Kc;` as before.
Preprocessor macros used to switch between.
* ultralcd.cpp defines extra menus for extra parameters only where
required
* M301 reports `e:xx` only if independent pid parameters enabled
* EEPROM structure still leaves space for 3 extruders worth, when undef
will save single parameter to all extruder positions, but only read the
first
* Switching off saves approx 330 B with no LCD enabled, 2634B with LCD
(RRD) enabled: this is significant.
* LCD modifications should be tested.

This change introduces an improvement to G29 command on Marlin.

Auto bed leveling operation's reliability is based on the repeatability of the Z-probe switch and the servo. This change introduces an option to G29 command. When the G29 command is sent with an "e" option, during auto bed levelling the servo is not retracted between probes which decreases the bias on auto bed levelling resulting from servo.

G29 command does the auto bed probing as it is.

G29 E command engages the servo on first probing point, probes all points and retracts the servo after probing the last point.

Please comment your opinions, test on your printer and check the code on a programmer's perspective. (I am not a good programmer.)