add tmp- prefix to temporary envs

Change-Id: Iaa07effd87dd2400ab79727379175bd80fd9bae6

Author: dhellmann

docs/source/history.rst

@@ -2,6 +2,12 @@
 Release History
 ===============
 
+dev
+===
+
+- Add ``tmp-`` prefix to temporary environment names created by
+  :ref:`command-mktmpenv`.
+
 4.1.1
 =====
 

virtualenvwrapper.sh

@@ -1106,6 +1106,7 @@ function mktmpenv {
         # This python does not support uuid
         tmpenvname=$("$VIRTUALENVWRAPPER_PYTHON" -c 'import random,sys; sys.stdout.write(hex(random.getrandbits(64))[2:-1]+"\n")' 2>/dev/null)
     fi
+    tmpenvname="tmp-$tmpenvname"
 
     # Create the environment
     mkvirtualenv "$@" "$tmpenvname"