implemented first version of ltm manager class for mongodb storage

...I/components/armem/server/ExampleMemory/ExampleMemory.cpp

...obotAPI/interface/armem/server/LoadingMemoryInterface.ice

source/RobotAPI/libraries/armem/CMakeLists.txt

source/RobotAPI/libraries/armem/client/Reader.cpp

source/RobotAPI/libraries/armem/core/MemoryID.cpp

source/RobotAPI/libraries/armem/core/MemoryID.h

source/RobotAPI/libraries/armem/core/base/MemoryBase.h

...otAPI/libraries/armem/core/longtermmemory/CoreSegment.cpp

...obotAPI/libraries/armem/core/longtermmemory/CoreSegment.h

...e/RobotAPI/libraries/armem/core/longtermmemory/Entity.cpp

source/RobotAPI/libraries/armem/core/longtermmemory/Entity.h

...PI/libraries/armem/core/longtermmemory/EntityInstance.cpp

...tAPI/libraries/armem/core/longtermmemory/EntityInstance.h

...PI/libraries/armem/core/longtermmemory/EntitySnapshot.cpp

...tAPI/libraries/armem/core/longtermmemory/EntitySnapshot.h

...e/RobotAPI/libraries/armem/core/longtermmemory/Memory.cpp

source/RobotAPI/libraries/armem/core/longtermmemory/Memory.h

...I/libraries/armem/core/longtermmemory/ProviderSegment.cpp

...API/libraries/armem/core/longtermmemory/ProviderSegment.h

source/RobotAPI/libraries/armem/core/wm/json_conversions.h