This is the easiest way to make button pin testing consistent without
renaming all the button pins. Just make a macro especially for testing
if button pins are set, since they are named consistently in the pins
files.

Update Kana font

Fix an error when EXTRUDE_MINTEMP is not defined

Fix servo deploy/stow issues with G29 and Delta

Fix string issues in ultralcd.cpp

FILAMENT_SENSOR -> FILAMENT_WIDTH_SENSOR

Show a warning message when Arduino IDE is prior to 1.5

Fix temperature checking conditions (backwards!)

Update U8glib URL

M104 not starting the print timer

Echo all debug levels in M111, default to DEBUG_NONE

Redo of #3268 by @jbrazio

Refinements, fixes, reduced stack usage in CardReader

M190 bed temp is never reached

Minor cleanup to filament sensor code

Keep blinking limited to LCD_UPDATE_INTERVAL

Cleanup, simplification of command dispatcher code

Relax the test for "Heating failed" errors

Formatted multi-line comments