- Docopt for CLI parsing

- Download, extract and Git checkout support
- OS specific keys with -win, -lin and -osx
- Force re-generation with -f flag

tests/nimgentest.nims

@@ -2,7 +2,6 @@ import ospaths
 import strutils
 
 for comp in @["nimbass", "nimfuzz", "nimssl"]:
-    cd(".."/comp)
-    exec "nimble install -y"
-    exec "nimble test"
-    cd(".."/"nimgen")
+    withDir(".."/comp):
+        exec "nimble install -y"
+        exec "nimble test"