fix #11: initialize queue_node_t n.next in msg_send()
fix for #87, replacing - with _ in module protocol_multiplex
fixed #18 for ICMPv6 packets
add cc110x_ng include path to transceiver module
fixes for #62: eliminate unused parameter warnings

NOTE: this commit introduces a kernel API change for mutex_unlock
fixing for #79: relocating rpl folder
some prototype fixes in RPL
Merge pull request #90 from OlegHahm/milestone_1_0_fixes

Milestone 1 0 fixes
Merge pull request #101 from authmillenon/master

Update .gitignore
Implement simple echo request/reply
Add missing packet length
Fix icmp echo packet lengths
Set up new directory structure
Move error codes to public includes
Make sixlowpan module more coding conventions compliant
Add documentation group for 6LoWPAN module
Update documentation of ipv6.h
Document sixlowpan/error.h