compile-time test support

This change brings 3 new items to `unittest2`:

* `-d:unittest2Static` compile-time flag that enables `test` to run both
at compile time and runtime
* `staticTest` that only run at compilet ime no matter the flag
* `runtimeTest` that only run at run time no matter the flag

tests/tunittest.nim

@@ -41,12 +41,10 @@ test "unittest typedescs":
   check(none(int) == none(int))
   check(none(int) != some(1))
 
-
 test "unittest multiple requires":
   require(true)
   require(true)
 
-
 import random
 proc defectiveRobot() =
   randomize()
@@ -55,7 +53,7 @@ proc defectiveRobot() =
   of 2: discard parseInt("Hello World!")
   of 3: raise newException(IOError, "I can't do that Dave.")
   else: assert 2 + 2 == 5
-test "unittest expect":
+runtimeTest "unittest expect":
   expect IOError, OSError, ValueError, AssertionDefect:
     defectiveRobot()
   expect CatchableError:
@@ -67,50 +65,50 @@ test "unittest expect":
   expect Defect, CatchableError:
     if true: raise Defect.newException("Okay")
 
-var
-  a = 1
-  b = -1
-  c = 1
+  var
+    a = 1
+    b = -1
+    c = 1
 
-#unittests are sequential right now
-suite "suite with only teardown":
-  teardown:
-    b = 2
+  #unittests are sequential right now
+  suite "suite with only teardown":
+    teardown:
+      b = 2
 
-  test "unittest with only teardown 1":
-    check a == c
+    runtimeTest "unittest with only teardown 1":
+      check a == c
 
-  test "unittest with only teardown 2":
-    check b > a
+    runtimeTest "unittest with only teardown 2":
+      check b > a
 
-suite "suite with only setup":
-  setup:
-    var testVar {.used.} = "from setup"
+  suite "suite with only setup":
+    setup:
+      var testVar {.used.} = "from setup"
 
-  test "unittest with only setup 1":
-    check testVar == "from setup"
-    check b > a
-    b = -1
+    runtimeTest "unittest with only setup 1":
+      check testVar == "from setup"
+      check b > a
+      b = -1
 
-  test "unittest with only setup 2":
-    check b < a
+    runtimeTest "unittest with only setup 2":
+      check b < a
 
-suite "suite with none":
-  test "unittest with none":
-    check b < a
+  suite "suite with none":
+    runtimeTest "unittest with none":
+      check b < a
 
-suite "suite with both":
-  setup:
-    a = -2
+  suite "suite with both":
+    setup:
+      a = -2
 
-  teardown:
-    c = 2
+    teardown:
+      c = 2
 
-  test "unittest with both 1":
-    check b > a
+    runtimeTest "unittest with both 1":
+      check b > a
 
-  test "unittest with both 2":
-    check c == 2
+    runtimeTest "unittest with both 2":
+      check c == 2
 
 suite "bug #4494":
     test "Uniqueness check":
@@ -187,4 +185,3 @@ when defined(testing):
 
 # Also supposed to work outside tests:
 check 1 == 1
-