cmake: allow the FSAL_DESTINATION to be overwritten

In certain environments, the library pathes are no longer
lib, lib32, and lib64 - such as Debian based systems that support
multiarch where the library path for the 64-bit architectures
are actually /usr/lib/x86_64-linux-gnu/ganesha and use the gnu
tuple based definition for the library.

So, to maintain backwards compatibility just allow an
override to cmake that can install the FSAL modules into
a different location.

Usage:

$ cmake -DFSAL_DESTINATION=lib/x86_64-linux-gnu/ganesha

Signed-off-by: Charles Hardin <ckhardin@gmail.com>
cmake: use the environment DESTDIR override for python installs

In several packaging steps, the DESTDIR is specified to install
the results to a local directory without changing the prefix
of the compilation.

So, in this case use the DESTDIR for the python installation
command to avoid any attempts to install to the root "/usr"
path when doing package installs.

Signed-off-by: Charles Hardin <ckhardin@gmail.com>
cmake: add a debian cmake build configuration

In the long run, the cmake packager can be used to create the debian
package by adding all of the appropriate glue definitions into this
file.

In the short term, this configuration is just referenced from
the debian/rules to trampoline from a "git-buildpackage" or a
"dpkg-buildpackage" command into the debian specific build
configuration.

Signed-off-by: Charles Hardin <ckhardin@gmail.com>
debian: update the debian configuration for packaging

Update to a 2.1.0 package and remove the specific 1.5.0 patches.

Rough cut, can easily be refined from here

Signed-off-by: Charles Hardin <ckhardin@gmail.com>