Ubuntu_16.04_LTS build instructions

[Wm]

Thanks to whoever did the new Ubuntu_16.04_LTS build instructions

https://wiki.gnucash.org/wiki/Building#Ubuntu_16.04_LTS_.28Xenial_Xerus.29

they worked nicely for me except I didn't have the tree under

$HOME/.local/share/GnuCash

and ended up building, creating missing dir, repeat to get it fixed.

The consequences of the missing dirs might put off future builders as it 
is reported as guile stopping unexpectedly and generates a system crash 
report way out of proportion to the actual problem.

I haven't found a list of the required directories but presume it must 
be somewhere in the new build files, the easy fix being to make or check 
existence of the tree before starting the build or to create them as 
needed during the build.

On a much more minor note the build instructions sometimes refer to the 
source dir as
../gnucash.git
and at others
../gnucash
not a big deal but an inconsistency that again might put someone off.  I 
prefer gnucash.git as I doubt many people are using anything else as 
their source these days.

In general I like the new build flexibility and will try some 
experimenting when time allows, maybe even try Windows and python again