build-sys: move to non-recursive build

This rather large change will attempts to make 'make' to work better.
See excellent paper 'Recursive Make Considered Harmful' by Peter Miller
for further explanation why several make files is worse than one for
whole project.

Reference: http://miller.emu.id.au/pmiller/books/rmch/
Reference: http://karelzak.blogspot.co.uk/2013/02/non-recursive-automake.html