grc: snap-to-grid (WIP)
grc: one preferences handler for all bools
grc: toggle action and mod1 modifier for snap-to-grid
grc: fix block height
cmake: fix typo in FindUHD.
cmake: add compiler flag only if the compiler supports it
cmake: remove verbose messages from UseSWIG.
Merge remote-tracking branch 'gnuradio-wg-grc/grc_snap_blocks_to_grid'
Merge remote-tracking branch 'michaelld/fix_typo'