Housekeeping on master branch

[Geert Janssens]

As briefly mentioned on the 2.8 roadmap thread I'm doing some major 
housekeeping on the master branch. This involves a lot of shuffling files and 
directories around.

IMPORTANT ANNOUNCEMENT FIRST: once this work goes into master, you will need 
to clear your build and installation directories and rerun autogen.sh/
configure or cmake again once!

And now on to some more details:

So far I have
- eliminated src/business. All relevant files have been moved to either src/
register or src/gnome. This was the last remaining bit for integrating 
business into the gnucash core.
- de-modularized the scheme-only directories standard-reports and utility-
reports. There was no advantage in this added boilerplate.
- merged src/libqof/qof back into src/engine. Functionally they have always 
formed one unit. Part was as some point split up in an effort to make it an 
independent system library. As this hasn't worked out, time has come to 
simplify our code again by uniting these two.

I'm deliberately doing this very late in the gnucash 2.8 development cycle to 
minimize the merge issues from maint to master. After the reshuffling there 
may be more of such issues.

As this work touches lots and lots of files it may also cause merge conflicts 
with local branches of the other devs. I have found git handles moving and 
renaming files quite well so I expect no merge conflicts on that level. 
However each renamed/moved file will also entail a change in a Makefile.am/
CMakeLists.txt file, which may cause conflicts if your local branches have 
changes in those.

For that reason I havent merged this branch into master right away. Instead 
for now it lives publicly here:
https://github.com/gjanssens/gnucash/tree/reorganize-source-dirs

Those with merge concerns, try to pull this branch locally and see if you get 
merge conflicts by merging your local branches into mine. If you need help 
with this, just let me know, here or on irc.

If there are no major issues by the end of the week, I will go ahead and push 
the branch to master.

Regards,

Geert