Mark items as deprecated in 1.2 release for removal in future major version

[rikoe]

The proposal is to mark the following features as deprecated in FDC3 1.2, for removal as part of the next major version of FDC3:

• IntentResolution.data property (Intent resolution data clarification #219)
• global channel (Remove concept of 'global' channel, context broadcast should always be opt-in #308)
• problematic signature of addContextListener (Argument order in addContextListener overloads complicates implementation #215)