test,libtracker-fts: allow alternate number of expected words

In ICU 50 the word splitting algorithm changed, so this test may get
different results depending on the host environment. The test simply
needs to verifying that word splitting works, so it should allow either
value.

As of November 2013 Ubuntu is still shipping an older version of ICU so
it would be awkward to simply increase the version we depend on.

https://bugzilla.gnome.org/show_bug.cgi?id=699412
tests: Avoid invalid calls to g_source_remove().

GLib now warns if removing a source that no longer exists.

This was causing intermittent failure of tracker-file-notifier-test
If the test timeout executed before the test's main loop exited, the
following error would occur:

        GLib-CRITICAL **: Source ID 130 was not found when attempting to
        remove it

The functional tests have also been fixed.
tests: Fix failure in tracker-sched-test under jhbuild

jhbuild defaults to running under 'SCHED_IDLE'. The test asserts that
the test is initially using 'SCHED_OTHER' -- this is a bad idea, we
shouldn't be making assertions about the environment in which the user
is running the tests.