Remove the Python 2.4 dependency and use just 'python'

Many Linux distributions are including python2.5 by default, as
it is the latest stable release of the language.  Using python2.4
(and asking users to specifically install it) is just cruel and
unusual punishment.

Signed-off-by: Shawn O. Pearce <sop@google.com>
diff --git a/main.py b/main.py
index 5609299..85c2941 100755
--- a/main.py
+++ b/main.py
@@ -15,7 +15,7 @@
 # limitations under the License.
 
 magic='--calling-python-from-/bin/sh--'
-"""exec" python2.4 -E "$0" "$@" """#$magic"
+"""exec" python -E "$0" "$@" """#$magic"
 if __name__ == '__main__':
   import sys
   if sys.argv[-1] == '#%s' % magic:
diff --git a/repo b/repo
index d5f69fb..18d0d7f 100755
--- a/repo
+++ b/repo
@@ -20,7 +20,7 @@
 # limitations under the License.
 
 magic='--calling-python-from-/bin/sh--'
-"""exec" python2.4 -E "$0" "$@" """#$magic"
+"""exec" python -E "$0" "$@" """#$magic"
 if __name__ == '__main__':
   import sys
   if sys.argv[-1] == '#%s' % magic:
@@ -28,7 +28,7 @@
 del magic
 
 # increment this whenever we make important changes to this script
-VERSION = (1, 4)
+VERSION = (1, 5)
 
 # increment this if the MAINTAINER_KEYS block is modified
 KEYRING_VERSION = (1,0)