initial implementation of API-REST-collect

The full documentation is available on the forge:
http://forge.fusioninventory.org/projects/fusioninventory-agent/wiki/API-REST-collect
add getRegistryValues() function
support WMI and more
minor
Merge branch '2.3.x' into 2.3.x+collect
Merge branch '2.3.x+collect' into master+collect
Merge remote-tracking branch 'origin/master' into master+collect
drop some debug print
do not use WMI on !Win32
new getInstance function
use getInstance to load backends
split config backends from Config class

This will allow for additional configuration backends later, such as
LDAP for instance.
Merge remote-tracking branch 'origin/master' into master+collect
Merge remote-tracking branch 'origin/master' into master+collect
disable the runCommand function

As decided by the FusInv-Agent developers, the runCommand
function is disabled for the moment.
clean up
Merge branch 'master+config-backend'