gr-filter: Add missing break statement.

Addresses Coverity issue 1046186. Although users are likely better off using
the Hamming window instead of a rectangular window, this error will confuse
knowledgable users.

Signed-off-by: Philip Balister <philip@balister.org>
filter: Fixing the Hilbert transform and QA.

The hilbert_fc block now takes the type of window as a parameter. Defaults to Hamming to a) maximize sidelobe suppression and b) that's how it's always behaved.

The QA codes were fixed to create Hilbert transform taps using Hamming window to account for the previous commits change to the rectangular window.
filter: fixed filter QA to calculate filter and delay instead of using previously generated samples.
filter: fixed some QA code to compute the output instead of using previously generated samples.
Merge branch 'maint' of git.gnuradio.org:gnuradio into maint