New build system in "master" branch

[Alan DeKok]

  OK... I've pushed some fixes.

  There might still be build errors if you don't have headers/libraries
installed.  e.g. rlm_python, rlm_perl, etc.  The short-term solution is
just:

$ rm src/modules/rlm_python/all.mk

  etc.

  The issue is that the new build isn't integrated with the "configure"
system.  I'll fix that at some point.

  But it now works for me on Mac && Linux.  "make install" should work,
too, with full dependency checking:

$ make R=~/fr install
...


$ touch src/lib/dict.c
$ make R=~/fr install
CC src/lib/dict.c
INSTALL libfreeradius-radius.la
INSTALL radeapclient
INSTALL smbencrypt
INSTALL radclient
INSTALL radiusd

  I don't normally type "make install" when I'm doing development.  This
is because the previous build system took ~20s to do a re-build and
re-install of everything.  The new system tracks dependencies across
source -> object -> installation.  So it's MUCH better, and MUCH faster.

  It's not enabled by default, because there are still some bugs to be
worked out.  But I'll be using it for all future development.

  Alan DeKok.