examples: fix rx_samples_to_udp bytes vs samples
utils: images downloader defaults to UHD_IMAGES_DIR instead of CMAKE_INSTALL_PREFIX
utils: cal apps immediately fail if dboard has no serial instead of after test runs
lib/cmake: CPack source work

* Removed all host code dependencies on firmware headers
* Put in CMake settings for CPack source
Merge branch 'maint34' into maint

Conflicts:
	host/lib/usrp/b100/b100_impl.cpp
	host/lib/usrp/usrp1/usrp1_impl.hpp
docs: fixed typo
xcvr2450: created xcvr2450 r21 that uses external divider
Fix syntax in XCVR driver.
wbx: expand freq range low for r4
Merge branch 'xcvr2450_r21' into maint34
Merge branch 'maint34' into maint
utils: usrp_n2xx_simple_net_burner accepts empty response to reset USRP
Modify query_gpsdo_sensors to wait long enough to latch a PPS in before checking it.