promote test-definition concepts from torture to base layer; reorganize tests to be nested in their respective layer; eliminate 't_group', just use containing layer

project.raddbg

@@ -6,7 +6,6 @@ target:
   executable: "build/raddbg.exe"
   working_directory: build
   arguments: "--user:raddbg_test.user --project:raddbg_test.project"
-  enabled: 1
   debug_subprocesses: 0
 }
 target:
@@ -38,3 +37,9 @@ target:
   working_directory: build
   arguments: "--rdi raddbg.pdb"
 }
+target:
+{
+  executable: "build/torture.exe"
+  working_directory: "build/"
+  enabled: 1
+}