Add package dir as a proper python site dir

nsist/commands.py

@@ -6,9 +6,12 @@ from .util import text_types
 
 SCRIPT_TEMPLATE = u"""#!python
 import sys, os
+import site
 installdir = os.path.dirname(os.path.dirname(__file__))
 pkgdir = os.path.join(installdir, 'pkgs')
 sys.path.insert(0, pkgdir)
+# Ensure .pth files in pkgdir are handled properly
+site.addsitedir(pkgdir)
 os.environ['PYTHONPATH'] = pkgdir + os.pathsep + os.environ.get('PYTHONPATH', '')
 
 # Allowing .dll files in Python directory to be found