Telnetd improvement: allow specifying a maximum silence time and kill the connection after that time. This is to avoid the telnet connection getting stuck forever if the connecting host reboots.
Added a number of default options for ContikiMAC, and allow them to be overridden with contiki-conf.h configuration options
Allow proactive probing interval to be configured
Allow platform makefiles to specify APPS to be used, by defining a PLATFORMAPPS variable.
Bugfix: when a CSMA callback is received, we should remove the packet
that was transmitted and not just the first packet that happens to be on
the output queue.
examples/trickle-library: correct probability expression

Documented intent is to update with probability 1/NEW_TOKEN_PROB where
NEW_TOKEN_PROB is 0x80.  The current implementation updates with probability
1/2.  Update NEW_TOKEN_PROB and the expression to keep existing behavior
while correcting the calculation.

Signed-off-by: Peter A. Bigot <pab@pabigot.com>
Merge pull request #270 from pabigot/push/trickle-example

examples/trickle-library: correct probability expression
Fixed option header bug for large deltas.
Limited observe clock to 24 bits.
Updated buffer definition macro due to core changes.
Updated copyright information.
Updated Erbium (Er) examples and removed unsupported static routing module.
Fixed RPL configuration according to core changes.
Added CoAP ping support.
Fixed stimer issues due to core changes for older Erbium versions.
Fixed broken/unclear Ipv6 configuration with CFLAG.
Merge pull request #177 from adamdunkels/feature-config-improvements

Configurability updates
Temporarily disable large RPL network test until we get link-layer ACKs in Cooja
Merge pull request #257 from adamdunkels/hotfix-csma

CSMA bugfix
Makefile.include: support extending CLEAN with directories

Use recursive remove for $(CLEAN) to support applications that extended it
with directories that should be removed.