digital: scrambler gets tag support
digital: added scrambling feature to OFDM tx/rx
cmake: update revision to 3.7.0.1 for release
Merge branch 'maint'

Use merge strategy -s ours to skip release commit.
cmake: update revision to 3.7.2git
Merge branch 'master' of git://github.com/gnuradio/gnuradio into scrambler
digital: Python functions to support soft decision making and look-up table generation.
digital: Added a new constellation_soft_decoder block that produces soft decisions as floats instead of hard decisions.

Added documentation for how to use the new soft decision tools.
digital: added a constellation modulator that uses a constellation object to modulate samples.

The constellation object knows the constellation and symbol mappings for any constellation, not just PSK or QAM.
new volk inverse square root kernel and agc3 speedups
Merge branch 'maint'
Merge branch 'maint'
runtime: exporing high_res_timer functions into Python (can be replaced by native Python calls with Python 3.3).
runtime: Added a Performance Counter that stores the accumulated work_time counter (work_time_total).
Merge branch 'maint'
Merge branch 'maint'
Merge branch 'maint'
Merge branch 'maint'
Merge branch 'maint'
Merge remote-tracking branch 'osh/agc3_speedups'