This change adds a layer of abstraction over poolmgr. Poolmgr is now just one of the ways to turn a function into a service; other implementations will be added. The executor abstraction is a uniform API over all these implementations.
* Executor layer added on top of pool manager
* Removed the external server for executor
* Minor changes to keep existing semantics as much possible
* Separating the executor vs. poolmgr backend functionality and associated data members
* Executor logic separated from Poolmgr backend completely, placeholder for new backend
* Changed references to poolmgr in tests
* Moved poolmgr to it's package, as a side effect moved Cache to its's package (was causing cyclical dependency) and had to make some data structures exposed outside package
* Rebased from master and changed references to tpr -> crd
* Executor layer added on top of pool manager
* Executor logic separated from Poolmgr backend completely, placeholder for new backend
* Changed podName to a generic objectReference in fscache (#391)
Changed podName to a generic objectReference in function service cache implementation.
* Moved poolmgr to it's package, as a side effect moved Cache to its's package (was causing cyclical dependency) and had to make some data structures exposed outside package
* Rebased from master and changed references to tpr -> crd
* Merged from master with latest changes
* Removed stale executor service & deployment from previous merge
* Addressed review comments, still testing some areas
