Remove get_os_release() / compare_versions()

The sole purpose of these functions was to determine whether or not
to use CLOCK_MONOTONIC_RAW (which is available on Linux 2.6.3+). Since we are
no longer using CLOCK_MONOTONIC_RAW, they are not necessary.

monotonic.py

@@ -41,7 +41,6 @@
 import ctypes
 import ctypes.util
 import os
-import platform
 import re
 import sys
 import time
@@ -50,18 +49,6 @@
 __all__ = ('monotonic',)
 
 
-def get_os_release():
-    """Get the leading numeric component of the OS release."""
-    return re.match('[\d.]+', platform.release()).group(0)
-
-
-def compare_versions(v1, v2):
-    """Compare two version strings."""
-    def normalize(v):
-        return map(int, re.sub(r'(\.0+)*$', '', v).split('.'))
-    return cmp(normalize(v1), normalize(v2))
-
-
 try:
     monotonic = time.monotonic
 except AttributeError: