Remove all the with ... as foo constructs

Those constructs have been introduced in Python 2.6, and some of our
autobuilders still use Python 2.5, so replace them with constructs
that are compatible with Python 2.5.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

Index: b/SConstruct
===================================================================
--- a/SConstruct
+++ b/SConstruct
@@ -366,8 +366,8 @@
 
 def CheckXsltproc(context):
     context.Message('Checking that xsltproc can make man pages... ')
-    with open("xmltest.xml", "w") as ofp:
-        ofp.write('''
+    ofp = open("xmltest.xml", "w")
+    ofp.write('''
        <refentry id="foo.1">
       <refmeta>
         <refentrytitle>foo</refentrytitle>
@@ -380,6 +380,7 @@
       </refnamediv>
     </refentry>
 ''')
+    ofp.close()
     probe = "xsltproc --nonet --noout '%s' xmltest.xml" % (docbook_man_uri,)
     ret = context.TryAction(probe)[0]
     os.remove("xmltest.xml")
@@ -1042,8 +1043,9 @@
 # build timebase.h
 def timebase_h(target, source, env):
     from leapsecond import make_leapsecond_include
-    with open(target[0].abspath, 'w') as f:
-        f.write(make_leapsecond_include(source[0].abspath))
+    f = open(target[0].abspath, 'w')
+    f.write(make_leapsecond_include(source[0].abspath))
+    f.close()
 env.Command(target="timebase.h", source="leapseconds.cache",
             action=timebase_h)
 
@@ -1116,15 +1118,17 @@
         ('@DEVMAIL@',    devmail),
         ('@LIBGPSVERSION@', libgps_version),
         )
-    with open(str(source[0])) as sfp:
-        content = sfp.read()
+    sfp = open(str(source[0]))
+    content = sfp.read()
+    sfp.close()
     for (s, t) in substmap:
         content = content.replace(s, t)
     m = re.search("@[A-Z]+@", content)
     if m and m.group(0) not in map(lambda x: x[0], substmap):
         print >>sys.stderr, "Unknown subst token %s in %s." % (m.group(0), sfp.name)
-    with open(str(target[0]), "w") as tfp:
-        tfp.write(content)
+    tfp = open(str(target[0]), "w")
+    tfp.write(content)
+    tfp.close()
 
 templated = glob.glob("*.in") + glob.glob("*/*.in") + glob.glob("*/*/*.in")
 
@@ -1560,9 +1564,10 @@
 def validation_list(target, source, env):
     for page in glob.glob("www/*.html"):
         if not '-head' in page:
-            with open(page) as fp:
-                if "Valid HTML" in fp.read():
-                    print os.path.join(website, os.path.basename(page))
+            fp = open(page)
+            if "Valid HTML" in fp.read():
+                print os.path.join(website, os.path.basename(page))
+            fp.close()
 Utility("validation-list", [www], validation_list)
 
 # How to update the website