* do not use V8 variant of AQL functions in early optimization stage when a C++ variant is available
* additionally, simplify AQL function definitions and aliases
* warn when more than 90% of max mappings are in use
* added C++ variant of replication catchup
* added `--log.role` option
* updated CHANGELOG
* removed non-existing scheduler.threads option from config
* removed useless __FILE__, __LINE__ invocations
* updated CHANGELOG
* allow a priority V8 context
* remove TRI_CORE_MEM_ZONE
* try to fix Windows errors & warnings
* cleanup
* removed memory zones altogether
* exclude system collections from collection tests
This allows changing the internals of TRI_vector_t structs in order to make the struct smaller.
On 64 bits, the size of TRI_vector_t is reduced from 48 bytes to 28 bytes.
TRI_json_t does benefit from this, as its biggest component is a TRI_vector_t.