Merge into master from pull request #42:
Big pull request - mainly to get the loxi_ir changes in (https://github.com/floodlight/loxigen/pull/42)
Mask values in a match according to its masks

A step towards match canonicalization.  When generating a match
structure, clear the bits outside of those indicated by the
masks.  Changes to test code to make consistent.

For 1.0, need only worry about IPv4 addrs.  Otherwise, use a simple
loop to iterative over bytes in the match.
Merge into master from pull request #44:
Mask values in a match according to its masks (https://github.com/floodlight/loxigen/pull/44)
Merge into master from pull request #43:
A few improvements to java_gen from the plane... (https://github.com/floodlight/loxigen/pull/43)
README.md: this actually requires python2.7+
Merge into master from pull request #45:
README.md: this actually requires python2.7+ (https://github.com/floodlight/loxigen/pull/45)
Merge branch 'master' of github.com:floodlight/loxigen
Merge remote-tracking branch 'yotam/master'
Merge remote-tracking branch 'yotam/master'
Richer model for OXMs
Reorganized OFFactories
Various improvements for the of classes
Various improvements for pre-written base types (U8 etc.)
remove getMatch() - replaced with build()
Added documentation for import_cleaner
Merge branch 'master' of github.com:andi-bigswitch/loxigen
Added mapping for OXM <-> Value Types for all match fields.
Implementation of the Match porcelain interface for OF version 1.3:
1. Renamed ENUM values in MatchFields to conform with the OF spec to allow unified code generation.
2. Extended OFOxms factory with methods for creating OXM objects from a given field and value. This code is automatically generated from the oxm_map in java_model.
3. Implemented OFMatchV3Ver13.java custom template.
4. Implemented OFMatchV3Ver13.Builder.java custom template.

Tested new implementation on demo controller and it works.