membase-cli, ep-engine & bucket-engine need agree on who installs mc_bin_client.py into $PREFIX/lib/python otherwise parallel build is subtly broken

SUBJ. See below what this is causing:

I've just found that ep-engine and membase-cli and bucket-engine all of them install it into $PREFIX/lib/python. And while there's dependency in bucket-engine on ep-engine, there's no dependency at all between those two and membase-cli. That's causing completely random final version of mc_client_binary.py

NOTE: membase-cli and ep-engine seemingly install sample (according to md5sum) version of file. But bucket-engine's version differs.

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1. ../../install/bin/cbepctl lh:12000 stop
   Traceback (most recent call last):
   File "/root/src/altoros/moxi/repo20-64/install/lib/python/cbepctl", line 169, in <module>
   c.execute()
   File "/root/src/altoros/moxi/repo20-64/install/lib/python/clitool.py", line 58, in execute
   f[0](mc, *args[2:], **opts._dict_)
   File "/root/src/altoros/moxi/repo20-64/install/lib/python/cbepctl", line 35, in g
   f(*args[:n])
   File "/root/src/altoros/moxi/repo20-64/install/lib/python/cbepctl", line 63, in stop
   mc.stop_persistence()
   AttributeError: 'MemcachedClient' object has no attribute 'stop_persistence'