CC2538: add support for UART baudrate 9600, 38400 and 57600
Ensure that the file end is updated in the original file extent if it has been overwritten through a micro log operation.
CC2538: add secondary location to ieee address

The CC2538 currently has two addressing options: a hardcoded address set
at compile time or the address stored in primary address section of the
info page. This commit adds the option to choose the secondary location
of the ieee address from the info page, or any memory address.

To use, define `IEEE_ADDR_CONF_USE_SECONDARY_LOCATION` in `project-conf.h`
or similar.

For example:

    #define IEEE_ADDR_CONF_USE_SECONDARY_LOCATION 1
Added bootloader backdoor configuration for cc2538DK in contiki-conf.h and selector in startup-gcc.c. Updated Makefile.cc2538dk to support direct uploading. Also updated the platform readme to include the workflow with cc2538-bsl.
Added the cc2538-bsl submodule to the tools dir
Merge pull request #582 from nvt/coffee-file-end-fix

Make sure that Coffee updates the file end after a micro log write.
[cooja/mspsim] a single sky mote in cooja.config should be sufficient
Merge pull request #584 from lab11/cc2538-ieee-addr

CC2538: add secondary location to ieee address
Remove GNU indent tools
Fix a typo
Merge pull request #562 from Noolitic/CC2538_UART

CC2538: add support for UART baudrate 9600, 38400 and 57600
Merge pull request #551 from JelmerT/feature-cc2538-bsl

CC2538 serial boot loader python script
Merge pull request #588 from ejoerns/pull-req/cooja-conf-doublesky

[Cooja/mspsim] Remove duplicate sky mote from cooja.config
Merge pull request #589 from g-oikonomou/nuke-indent

Nuke indent