Fix too short 6LoWPAN reassembly timeout
llsec: Renamed ccm to ccm_star & Renamed llsec regression test
Makefile.include: Assign git description variable once.

By changing RELSTR= into RELSTR:= we force Make to evaluate the Git
version string only during Makefile read, and not on every single build
command execution.

The reduction in file system I/O cut the time to build
examples/er-rest-example on my development machine by a significant
amount, see below.

Core i7 notebook with ext4 file system on an SSD (building for TARGET=mulle):
"RELSTR="  make  19.70s user 1.07s system 82% cpu 25.291 total
"RELSTR:=" make  11.81s user 1.27s system 79% cpu 16.499 total

Signed-off-by: Joakim Gebart <joakim.gebart@eistec.se>
Merge pull request #841 from gebart/build-git-tag-io-reduce

Makefile.include: Reduce I/O load (and build time) by assigning git description variable once.
[cooja-platform] Include eeprom.h to avoid implicit declaration warning
[cooja-platform] Remove unused variable 'shortaddr'

This variable was set but never used in the code
[cooja-platform] Add cast to linkaddr_t to avoid warning
[cooja-platform] Fixes for slip-bridge compatibility

* Added dev/uart1.h header file to cooja platform
* Added slip arch stub
* Suppress examples putchar definition as cooja platform provides its own

Note that the uart1.h file should only be an intermediate solution.
A generic contiki-wide definition for uart handling is required as each
platform defines its own varying set of uart functions.
Button: Move common interface visualization to Button class

The implementation of a simple JPanel with a JButton was only code
duplication accross the several button implementations.
SkyButton: Reduce dependency on SkyMote

Placed call to setButton() in implementation-specific functions
doPressButton() and doReleaseButton() as in ContikiButton.
Button: None of the buttons will saves its state

Saving a buttons state in simulation file is not required as its state
is much too volatile.
Button: Add doPressButton() and doReleaseButton() to Button class

As every Button has a node-specific implementation part, this should be
the minimal interface to the backend node emulator for pressing and
releasing a button.
Buttons: Move implementation of button routines to Button class

The implementation of clickButton(), pressButton(), and releaseButton()
can be shared accross the several node-dependent implementations as
they use the node-dependent doPressButton() doReleaseButton() routines.
Buttons: Added missing @Override annotations
Buttons: Some minor cleanups

Removed imports not required anymore and made some class members final
Buttons: use non-deprecated MSPSim button api
Merge pull request #846 from ejoerns/pull-req/cooja-platform

Cooja platform fixes
New PluginType SIM_CONTROL_PLUGIN for sim control

SIM_CONTROL_PLGUIN are handled like SIM_PLUGIN, with one exception.
If the simulation is started with -nogui=<simfile> than it is checked
if a controlling plugin is loaded. If not, the simulation terminates
with an error message.
Better error message when aborting simulation
Button: Allow to press and release button by mouse and key

In the previous implementation a click event was triggered when the
button was pressed.
This implementation allows to set and release buttons independently both
by mouse clicking and by key typing.