new i2c sensor (tmp175) added

Signed-off-by: Patrick Hieber <p@trickhieber.de>
Change license to GPLv3 in order to be ethersex compliant.

Signed-off-by: Patrick Hieber <p@trickhieber.de>
license fix
tmp175 in menuconfig
Merge branch 'master' of github.com:phieber/ethersex
make rs485 transmit enable consistent in all modules
added eltakoms to usart-config.sh script
fixed C&P error
changed DMX timing according to DMX512-A recommendation
use atomic locking function for usart setup
again some C&P error
DMX transmit completely interrupt driven
Merge branch 'e6-upstream2' of github.com:sauttefk/ethersex into e6-upstream2

Conflicts:
	protocols/dmx/dmx.c
MODBUS also uses RS485 - rewrite for global RS485 TE config
MODBUS RS485
increase the timeout to 5 minutes

Signed-off-by: Maximilian Güntner <maximilian.guentner@gmail.com>
change bootload_delay to uint16_t

Signed-off-by: Maximilian Güntner <maximilian.guentner@gmail.com>
fix formatting

Signed-off-by: Maximilian Güntner <maximilian.guentner@gmail.com>
update checksum when saving a new value

Signed-off-by: Maximilian Güntner <maximilian.guentner@gmail.com>
fix formatting

Signed-off-by: Maximilian Güntner <maximilian.guentner@gmail.com>
add master boot record support

When booting, the bootloader should only wait for
a new image when either no image has been flashed yet or
the user explicitly wishes to update the image. Another reason
would be when a previous flash failed (image corruped, image doesn't
reach the main loop).

Apart from that, the bootloader should immidiately start the application.

The user can now invoke the extended delay by the already established
ECMD command "bootloader".

Signed-off-by: Maximilian Güntner <maximilian.guentner@gmail.com>