restructure project directory

- memdump and memload app are in their own folders
use EMBD_HOST environment vars to select hardware.

Don't like how embd code uses the hostname to determine what hardware
we are on. Set EMBD_HOST to RPi or RPi2 for Raspberry pi or BBB for
beaglebone black.
tools: script that build and upload application to device
detectHost: board had no type
build: forgot to rename file in Makefile
tools: build and push both memdump and memload to device