dont clean setuid bit on rtapi_app_xenomai
add a linuxcnc-test.deb, with all the tests in it

This commit is not ready yet.  FIXME:

    runtests gets installed gzipped and without execute permissions

    the runtests script tries to run scripts/rip-environment first thing :-/

The ubc branch has problems that our tests missed because we don't follow
the 'test like you fly' principle.

There are differences between run-in-place builds and installed builds,
and our current testing method only tests run-in-place, so we can miss
problems with installed configurations.  This commit adds a deb with
just our tests in it, so we can test installed programs too.
linuxcnc-test.deb: don't compress or clear execute permissions on the tests

FIXME: another problem with linuxcnc-test.deb is that the user doesn't
    have write permission to /usr/share/doc/linuxcnc/tests, so all the
    tests fail

With this commit, if i cp the tests directory to my home dir and edit
runtests to not try to source rip-environment, the tests start running.
Some tests pass.  Some still fail, and the runtests script itself falls
over part way into the test list.
Makefile:  install /etc files with correct permissions

Don't depend on a particular umask being set (buildbot!).

These files should be world-readable:
  /etc/udev/rules.d/50-LINUXCNC-shmdrv.rules
  /etc/security/limits.d/linuxcnc.conf
tests/bitops.0/test.sh:  change include dir to /include from /src/rtapi

Theory:  tests ought not to depend on anything in /src/
hm2-idrom test:  fix "too many arguments" error

Introduced by Y.T. in c6b87eec.  :P

From build log:

+ test -f realtime.log.0 realtime.log.1 realtime.log.10 realtime.log.11 [...]
test.sh: line 29: test: too many arguments

(Also, fix difficult-to-read test)
realtime.in:  recursively remove kmods and depending modules at unload

In kthreads flavors, when the realtime environment crashes badly
enough (e.g. linuxcncrsh starts during runtests but the test fails for
other reasons), 'trivkins', 'comp', and other modules that depend on
hal_lib and rtapi may be left loaded.  In this case, hal_lib and rtapi
cannot be unloaded without first removing those modules.

The RemoveModules function removes a list of modules recursively by
finding dependent modules in /proc/modules and removing them first.
mesa-hostmot2 driver:  Remove int->double conversions

Fixes 'Unknown symbol __fixunsdfdi' on 32-bit gcc-4.[34].x kthreads

Also see:

http://permalink.gmane.org/gmane.linux.distributions.emc.user/18718
http://permalink.gmane.org/gmane.linux.distributions.emc.devel/3663

(Several more in components/lcd.c parse_fmt() that'll be harder/uglier
to squash)