cbc: add version command
cbc: add version command

It could be useful to check if cbc and libcouchbase installed in linked
successfully, for example in homebrew scripts. (-? option is returning
EXIT_FAILURE)

Change-Id: I52b83e761f33c7803593a7a676a1bf44580c7ecd
Reviewed-on: http://review.couchbase.org/12266
Tested-by: Sergey Avseyev <87f6d5e4fd3644c3c20800cde7fd3ad1569370b3@gmail.com>
Reviewed-by: Trond Norbye <60edd2ef23891a753f231b0c6f161dc634079a93@gmail.com>

uvenum/libcouchbase,senthilkumaranb/libcouchbase,avsej/libcouchbase,avsej/libcouchbase,couchbase/libcouchbase,trondn/libcouchbase,senthilkumaranb/libcouchbase,trondn/libcouchbase,mnunberg/libcouchbase,avsej/libcouchbase,mody/libcouchbase,couchbase/libcouchbase,avsej/libcouchbase,mnunberg/libcouchbase,uvenum/libcouchbase,couchbase/libcouchbase,couchbase/libcouchbase,mody/libcouchbase,senthilkumaranb/libcouchbase,avsej/libcouchbase,uvenum/libcouchbase,couchbase/libcouchbase,avsej/libcouchbase,kojiromike/libcouchbase,signmotion/libcouchbase,signmotion/libcouchbase,signmotion/libcouchbase,kojiromike/libcouchbase,uvenum/libcouchbase,mody/libcouchbase,kojiromike/libcouchbase,mnunberg/libcouchbase,senthilkumaranb/libcouchbase,maxim-ky/libcouchbase,PureSwift/libcouchbase,PureSwift/libcouchbase,mnunberg/libcouchbase,trondn/libcouchbase,trondn/libcouchbase,PureSwift/libcouchbase,maxim-ky/libcouchbase,maxim-ky/libcouchbase,signmotion/libcouchbase,maxim-ky/libcouchbase,trondn/libcouchbase,mnunberg/libcouchbase,kojiromike/libcouchbase,PureSwift/libcouchbase,avsej/libcouchbase,mody/libcouchbase,couchbase/libcouchbase,uvenum/libcouchbase,couchbase/libcouchbase