* src/tgbaalgos/tau03opt.cc: Include <vector>.
(tau03_opt_search): Add option "ordering" (off by default). If enabled, initialize an explicit ordering for acceptance conditions into the new member "cond" (a vector of bdds). (project_acc): New helper function for projecting a set of acceptance conditions to a subset that maximizes the number of initial consecutive conditions covered by the set in the condition ordering. (dfs_blue): Implement the ordering heuristic. (dfs_red): Use a sentinel in condition_stack to avoid explicit checks for the stack's emptiness. Consider also the conditions in acc when checking for the completion of an accepting cycle. Fix the implementation of condition heuristic. Implement the ordering heuristic. Simplify the removal of elements from condition_stack (due to the way in which elements are pushed on the stack, there can be at most one element with a given depth in the stack at any one time).