Add u8glib library supporting dot matrix displays

https://code.google.com/p/u8glib/
Universal Graphics Library for 8 Bit Embedded Systems
Add Marlin (reprap) specific fonts 6x10, 6x9

Font size 6x10 with feedrate symbol & Font size 6x9.
Reduced u8glib SPI speed to fosc/8

Makes the lib compatible with most LCDs
Add bitmap graphics for GLCD

1. Marlin welcome screen
2. Status screen symbols 3 Extruders, heated bed, animated fan logo 1
3. Status screen symbols 3 Extruders, heated bed, animated fan logo 2
Marlin code for GLCD display

This contains the menues, status screen etc...
Add library selection between GLCD and char. LCD
Add variable for animated fan, add float conversion w/o sign

A new variable was introduced to allow fan animation on the GLCD.
Add additional float to string conversion routine without sign
character. This is used for the coordinates visualisation on the GLCD.
Add code to lcd_update() for GLCD

This code selects between the routines for the GLCD or the char.
display.
Removed debug code, add some comments
Modified u8glib logo on welcome screen
Add include selector between char. LCD and GLCD