config update
Fix network config requirement.

<network> node is mandatory. However, is <enabled>false</enabled> is present, we do not check for other network information, prevent invalid access in the property tree.
Unexport sysfsgpio when we are done
prepare for sysfsgpio refactoring
refactoring
refactoring
refactoring
Work on SysFsGpioModule.

SysFsGpioModule has been reworked. Not quite finished yet though.