Fix acceleration bug where an extruder only move was though to be a real move and uninitialized fields were being used to calculate trapezoids
Fix partial memory leak where the blocks gocde vector was not being cleared when it was popped from the tail
rename RingBuffer::delete_first() to delete)tail() to reflect what it actually does
Merge pull request #306 from wolfmanjm/upstreamedge

Fix acceleration bug, and memory leak
further fields that extruder needs to initialize
Merge pull request #307 from wolfmanjm/upstreamedge

further fields that extruder needs to initialize
Fix acceleration calculatin bug when preceded by extruder only move block (entry speed was not being set to zero)
Clean up block initialization, actually zero all block fields on ctor and add a clear() method
Merge pull request #308 from wolfmanjm/upstreamedge

Fix acceleration calculation bug when preceded by extruder only move bloc...
M500 save current settings for E only if different from the config value
Merge pull request #309 from wolfmanjm/upstreamedge

M500 save current settings for E only if different from the config value
Set previous_nominal_speed to 0 if the next block is a zero move block so jerk can be calculated correctly
clean up some stuff
Merge pull request #310 from wolfmanjm/upstreamedge

Set previous_nominal_speed to 0 if the next block is a zero move block s...
Make minimum planner speed configurable
pop all flushable blocks for queue in one on_idle
Add M205 Sxxx to set minimum planner speed from console and save with M500
Merge pull request #311 from wolfmanjm/upstreamedge

Make minimum planner speed configurable
Changed SerialConsole definition for MRI/Debug UART so it supports all 4 locations
Merge pull request #313 from powertomato/feature/mri_all_locations

Changed SerialConsole definition for MRI/Debug UART so it supports all 4...
provide one method to add gcode to blocks, reduce code duplication
add HeapRing: a new RingBuffer constructed from the trials and tribulations of the existing one
Change Conveyor,Planner,Block to use HeapRing
HeapRing: missed a free() in a corner case
Revert "Change Conveyor,Planner,Block to use HeapRing"

This reverts commit 5bd37b4d1309789eb1dc8f3300f0ee206901a171.