AADL stood/cheddar interoperability

[P. Dissaux]

Fix 2 bugs detected during AADL stood/cheddar interoperability experiments (see stood1.aadl test suites).

• To compute a DM scheduling, a control checked that all tasks are periodic. To compute scheduling simulation, there is no need to meet this assumption. Same trouble in the algorithm to compute priorities from deadlines.

• During the parsing of an AADL data, the Data_Concurrency_State was initialized by zero, blocking tasks at simulation time if the Cheddar properties Data_Concurrency_State is not provided. Data_Concurrency_State is now initialized by 1.