added utf8 encoding line to python templates

python breaks if it encounters special characters
in files without specified encoding.
Which is especially funny if you've got umlauts
in your name.
Created atsc_rx.py and removed obsolete scripts

Several bug fixes and speedups rolled into one ATSC
decoder script. The old method included separately
launched scripts linked with named pipes, this was
tedious and slowed down decoding, so I have moved
their functionality into one flowgraph.
Fix bugs in atsc_field_sync_mux.

Since this block inserts field syncs into the data stream, clearly
it needs to be a gr_block rather than a gr_sync_block.  Also, the
d_already_output_field_sync variable needs to be initialized and
the d_current_index variable is unusued and thus can be deleted.

With these fixes in place, I've successfully transmitted an MPEG
transport stream with a USRP N210 and received it on my television.
grc: checks for virtual/pad source/sink and ignores them for affinity and buffer size fields.
Merge remote-tracking branch 'mmueller/modtool_py_utf8' into maint
Merge branch 'maint'
wxgui: Prevent a crash at displaying the tooltip when the graph is not yet populated
Merge branch 'maint'
Merge remote-tracking branch 'glneo/atscfixup'
build: require Python v2 for build configuration
Merge branch 'maint'
runtime: fix asynch messages delivery when handler not defined
blocks: expose set_period callback for blocks.message_strobe in GRC
Merge branch 'maint'
Merge remote-tracking branch 'argilo/atscfixes2'
build: fix for finding and handling ICE 3.5 or 3.4
Merge branch 'maint'