qtgui: fixes some bugs between qwt 5 and 6, some reorg.
Merge branch 'maint'
Merge branch 'master' into next
blocks: interleaved_char_to_complex grc xml fix
digital: updated narrowband examples with --lo-offset and --clock-source options
digital: fixed ofdm benchmark_tx. flowgraph was closing down before tx queue was empty
Merge branch 'master' into next
fft: fix XML import for logpwrfft block
cmake: force detection to Python 2.x only
runtime: fix hier_block2 disconnect_all()
Merge branch 'maint'
Merge branch 'master' into next
utils: Fixes grcc to exit with an error code in case of a compilation error.
Merge branch 'maint'
grc: Sorts the block tree column at start-up.
Merge branch 'master' into next
blocks: adding a complex VCO block.
filter: added optional second input that dynamically adjusts resampling rate.
runtime: Fixed runtime SWIG linker error

* gnuradio_runtime_EXPORTS is not defined for SWIG builds by default, so this fix manually sets it for the runtime_swig build
Merge remote-tracking branch 'ncorgan/runtime_swig_fix' into maint