add line statements, new tests, c++11 in cmake

test/data/nested-line/data.json

@@ -0,0 +1,4 @@
+{
+    "xarray": [0, 1],
+    "yarray": [0, 1, 2]
+}

test/data/nested-line/result.txt

@@ -0,0 +1,6 @@
+0-0
+0-1
+0-2
+1-0
+1-1
+1-2

test/data/nested-line/template.txt

@@ -0,0 +1,6 @@
+## for x in xarray
+## for y in yarray
+{{x}}-{{y}}
+
+## endfor
+## endfor