increased the driver strangth of portD to supply the flash
workaround for some bugs: issue #216 (first ADC read is always corrupt), some busywait/atomic bug
packaging: update nesc build.sh

This updates the build.sh script in the packaging/nesc folder to nesc
1.3.5 (which now comes from github).
Merge pull request #257 from lab11/packaging-updates

packaging: update nesc build.sh
use channel 26 on all radios
Merge pull request #258 from szte-wsn/rfxxx_def_channel

Use channel 26 on all radios
Replaced timer-based BusyWait with a main clock based one, because timer-based caused infinite loop in long atomic sections
serial stack by @mmaroti Faster and smaller then the current one