board/pca1000x: added/fixed dist scripts

- pca10000: added author to debug.sh
- pca10005: added debug and reset scripts
- pca10005: fixed flash script
- pca10005: adjusted env vars in Makefile.include
rpl: mute RPL

Removes all but one occurrence of printf and puts within routing (the
remaining puts is called from a debug function.
add backspace functionality in shell
Add 0x7f as backspace key in shell
samr21-xpro: initial import for the samr21-xpro board
Merge pull request #1622 from haukepetersen/fix_pca_sripts

board/pca1000x: added/fixed dist scripts
Merge pull request #1701 from thomaseichinger/samr21

cpu/board: Initial import of samr21-xpro
native: -DNATIVE_INCLUDES if using NATIVEINCLUDES

It can be useful to know if the current compilation builds the native
board module, because e.g. then we must not include `sys/types.h`.

This diff adds `-DNATIVE_INCLUDES` to the make variable
`NATIVEINCLUDES`.
 core: Provide ssize_t in a common place

 Now you can include `kernel_types.h` if you need the `ssize_t`, without
 facing problems due to the terrible MSP toolchain.
stm32f0: be UART0 aware
stm32f4: be UART0 aware
stm32f3: be UART0 aware
stm32f1: unify UART0 use
stm32f*: rename STDIO buffer and enable getchar with UART0
Merge pull request #1471 from thomaseichinger/impl_uart0

cpu: make stm32f{0,1,3,4} comply to UART0 module
boards:mega2560: add debug and debug-server targets
Merge pull request #1696 from N8Fear/mega2560-debug

boards:mega2560: add debug and debug-server targets
drivers: import PIR motion sensor driver

Includes an application for manual testing.
Merge pull request #1714 from LudwigOrtmann/add_driver_pir

drivers: import PIR motion sensor driver
make: add objdump target