Changing OFMatch to OFRule, that now aggregate information about actions too.

This commit introduces the class OFRule, that represents an entry in an OpenFlow table.
It is basically a map of OpenFlow key,value pairs that get inserted in an OpenFlow switch
table. It is used by sdnPSS to parse an OF match and OF actions and to generate
the final Floodlight request. It also translates the entries in a format that Floodlight's
Static Flow Pusher understands.
Implementation of VLAN tagging in OFRule

This commit extends OFRule to include VLAN tagging.
It also includes lots of bug fixes and sanity checks.
This commit also includes the function reverse, which returns
a new OFRule with specifications on how to setup the "reverse"
circuit reservation (from destination to source).

Note that from now on all keys of OFRule are OpenFlow keywords.
The function floodlightEntrySet returns a set with key,values in
the format that Floodlight's Static Flow Pusher module will understand.
VLAN implementation for SDN PSS

With this commit, OFRule becomes a base component
for setting up a reservation using SDN PSS.
Minor change: replacing strings by static variables in OFRule.java
Bugfix: replacing Floodlight tokens by OF tokens for user input data