Split static and dynamic initialization. Allow reset of dynamic content by calling Init() again.

Discussion Basis

Relates to #48 (closed)

• Splits Init into static and dynamic content (SetupDynamicContent)
• Reset the Engine by calling SetupDynamicContent again
• Added increments random seeds between SetupDynamicContent calls
• Allows to fix or manually control the random seed via override
• Updates MantleAPI

Compiles if Reset-Methods are added to ControllerRepository and EntityRepository