Merged l1t-devel-CMSSW_7_2_0_pre6 from repository cms-l1t-offline
add demux algo classes
Move the plugin headers into the source files.
Remove hard-coded header and trailer lenghts.
Hook up (un)packer in the calo emulation.

Conflicts:
	L1Trigger/L1TCalorimeter/test/SimL1Emulator_Stage1.py
Produce collections even if the unpacking fails.

Required a reworking of the unpacker factory interface, which now includes
{begin,end}Event methods to create new collections and put them into the
event.
Simplify packing configuration.

The configuration now follows the same style as the unpacking one, where
customization is still possible on the basis of individual unpackers.
Simplify the unpacker constructor signature.
Introduce a collections object.

Keep all the collections in a central object to take care of sharing
collections and preventing collisions when putting content into the event.
Make FED ids internally consistent.
Use base constructors for unpackers.
Remove trailing whitespace.
Don't store collections in the unpackers.
Move to a central management of unpackers.

Unpackers are created via a central management module in terms of (FED ID,
AMC ID, block ID, FW ID).  This module now also registers the products with
the EDM framework and creates collection objects.
Get unpackers for a set of FED, AMC, FW ids.

These free ids fix a set of block ↔ unpacker associations, which are needed
for every AMC block.
fixes for stage1 non packetised data
fix tX data handling
Merged l1t-devel-CMSSW_7_2_0_pre7 from repository cms-l1t-offline
Update for 720pre7 release
Remove unneccessary xml's (already included in 720pre7)