Support for FreeBSD

We update the scripts to use `/bin/sh` instead of bash.  Also, a
small update to `CMakeLists.txt` is included for making debugging
a little easier.
Support the Tilera platform

This patch provides build and test script updates for the Tilera
platform.  The cmake scripts autodetect if you are configuring on a
system with a Tilera MDE installed, so you can use the normal `cmake`
command in a build directory with standard cmake options.  Note that
we turn off building the documentation on Tilera, even if Sphinx is
installed.

The major modification to our standard workflow is testing: replace
`make test` with `./tile-test`.  This assumes there is a working
connection to a Tilera device.

Installation requires sudo access, i.e., `sudo make install`. If you
intend to use these files regularly, then you should use an installation
prefix that includes `$TILERA_ROOT/tile`.  One good example is
`$TILERA_ROOT/tile/usr/local`, but you can use any directory you want
that is supported by the various `tile-monitor` upload and mount options.
Merge branch 'feature/freebsd' into c-template

* feature/freebsd:
  Support for FreeBSD
Specify network connection to tile-monitor

This patch updates the tile-test script to use a network connection
when connecting to a Tilera processor using tile-monitor.  This appears
to address the problem of slow execution and crash shepherd processes
when connecting over the (default?) serial connection.
Allow custom library installation directory

It turns out that some Linux distros (ahem, RHEL) want you to put 64-bit
libraries into /usr/lib64, not /usr/lib.  So we need to allow the user
to override the destination directory that we use when installing
libraries.  This new `CMAKE_INSTALL_LIBDIR` variable seems to be the
standard one to use.  We cannot rely on it being either a relative or
absolute path (see [1]), but the usage in this patch should work either
way.

[1] https://bugzilla.redhat.com/show_bug.cgi?id=795542
Warnings are errors on clang

We were setting -Wall -Werror when compiling with GCC to make sure that
we get rid of all compiler warnings as part of the standard build/test
process.  Now we do that for clang, too, for when we're developing on
Mac OS X.
Merge remote-tracking branch 'template/c-template' into develop

* template/c-template:
  Warnings are errors on clang
  Allow custom library installation directory
  Specify network connection to tile-monitor
  Support the Tilera platform
  Support for FreeBSD