Allow parameters to be designated as init time properties

[rabbah]

As discussed on the dev list, allows parameters to be designated as init time parameters. The result of such a designation is that the corresponding parameters are communicated to the action at initialization time and should be exported to the action's environment accordingly. This change requires updates to the action runtimes for the latter details and will be done separately. Additonal changes are required to the documentation once all the details are in place.

1. implement the core API change
2. extends all the runtimes
   1. nodejs
   2. c#
   3. all action loop related runtimes
3. update cli (Add -e)
4. update documentation (include examples of using this capability with wsk and functions)