Py3k: update OSX installer-generator

This update makes sure that the installer won't write files
in /usr/local/bin by default. The installer also won't
replace /Library/Frameworks/Python.framework/Version/Current.

Both to ensure that the installer doens't break an existing
install of python 2.x.

Mac/BuildScript/build-installer.py

@@ -184,6 +184,7 @@ PKG_RECIPES = [
             wrappers for lots of Mac OS X API's.
         """,
         postflight="scripts/postflight.framework",
+        selected='selected',
     ),
     dict(
         name="PythonApplications",
@@ -197,6 +198,7 @@ PKG_RECIPES = [
             It also installs a number of examples and demos.
             """,
         required=False,
+        selected='selected',
     ),
     dict(
         name="PythonUnixTools",
@@ -208,6 +210,7 @@ PKG_RECIPES = [
             is not necessary to use MacPython.
             """,
         required=False,
+        selected='unselected',
     ),
     dict(
         name="PythonDocumentation",
@@ -222,6 +225,7 @@ PKG_RECIPES = [
             """,
         postflight="scripts/postflight.documentation",
         required=False,
+        selected='selected',
     ),
     dict(
         name="PythonProfileChanges",
@@ -239,6 +243,7 @@ PKG_RECIPES = [
         topdir="/Library/Frameworks/Python.framework",
         source="/empty-dir",
         required=False,
+        selected='unselected',
     ),
     dict(
         name="PythonSystemFixes",
@@ -252,6 +257,7 @@ PKG_RECIPES = [
         topdir="/Library/Frameworks/Python.framework",
         source="/empty-dir",
         required=False,
+        selected='unselected',
     )
 ]
 
@@ -650,6 +656,8 @@ def buildPython():
     frmDir = os.path.join(rootDir, 'Library', 'Frameworks', 'Python.framework')
     gid = grp.getgrnam('admin').gr_gid
 
+
+
     for dirpath, dirnames, filenames in os.walk(frmDir):
         for dn in dirnames:
             os.chmod(os.path.join(dirpath, dn), 0775)
@@ -696,6 +704,11 @@ def buildPython():
 
     os.chdir(curdir)
 
+    # Remove the 'Current' link, that way we don't accidently mess with an already installed
+    # version of python
+    os.unlink(os.path.join(rootDir, 'Library', 'Frameworks', 'Python.framework', 'Versions', 'Current'))
+
+
 
 
 def patchFile(inPath, outPath):
@@ -830,7 +843,7 @@ def makeMpkgPlist(path):
             IFPkgFlagPackageList=[
                 dict(
                     IFPkgFlagPackageLocation='%s-%s.pkg'%(item['name'], getVersion()),
-                    IFPkgFlagPackageSelection='selected'
+                    IFPkgFlagPackageSelection=item['selected'],
                 )
                 for item in PKG_RECIPES
             ],