rename ext_rehashdir.py to ipy_rehashdir.py

IPython/Extensions/ipy_system_conf.py

@@ -15,7 +15,6 b' ip = IPython.ipapi.get()'
 
 import sys
 
-import ext_rehashdir # %rehashdir magic
 import ext_rescapture # var = !ls and var = %magic
 import pspersistence # %store magic
 import clearcmd # %clear

IPython/UserConfig/ipy_profile_sh.py

@@ -33,6 +33,7 b' def main():'
     import envpersist
     import ipy_which
     import ipy_stock_completers
+    import ipy_rehashdir
     
     
     ip.ex('import os')