remove californium dependencies of leshan.server.lwm2m.security and
leshan.server.lwm2m.impl.security package.
rename LwM2mServerImpl to LeshanServer and move it to
leshan.server.lwm2m package.
Do not override managed version of commons-codec
Use properties for defining version ranges of logging dependencies
replace the use of DDF file from OMA by our own json format.
Merge remote-tracking branch 'origin/master' into osgi-module

Conflicts:
	pom.xml
Use Scandium SNAPSHOT as a separate OSGi bundle instead of embedding it
into leshan-core