Merge branch 'feature/jst' into feature/jst_parallel

Conflicts:
	extras/include/seqan/journaled_string_tree/journaled_string_tree_traversal.h
	extras/include/seqan/journaled_string_tree/journaled_string_tree_traversal_branch_stack.h
	extras/tests/journaled_string_tree/test_journaled_string_tree_traverse.h
[INTERNAL] Modifies strategy to parallelize the JST traversal.
Merge branch 'feature/jst_parallel' into sandbox

Conflicts:
	extras/include/seqan/journaled_string_tree/journaled_string_tree_traversal.h
	extras/include/seqan/journaled_string_tree/journaled_string_tree_traversal_branch_stack.h
	extras/tests/journaled_string_tree/test_journaled_string_tree_traverse.h
Adds tests for parallel processing.
replaces code from jst_parallel