Coord: fixed the info() function

old: printed the pointer
new: print "(x, y, z)"
.gdbinit adjusted
.gitignore
tests: added Ieee80211 carrier sense tests.

Covers mutual transmissions for in range and out of range,
synchronized and delayed scenarios.
RTPHost moved from src/transport to src/nodes/

HOST MODELS MUST ALWAYS BE PLACED INTO nodes/ (or under an example simulation)
IPv4Address: rename getBroadcastAddress() to makeBroadcastAddress()

Also: added getNetworkBroadcastAddress() to IPv4InterfaceData
MACAddress: added makeMulticastAddress()
Ieee802Ctrl.inputPort renamed to interfaceId
IPv4: routing table: added a new route check