Introducing IPO to the CMake build process.

[tcormackMW]

Performance verified locally: does not seem to be causing regressions consistently... subject to consistency of local machine.

[codecov]

Codecov Report

Merging #951 (14a9fcf) into development (bce4a3e) will decrease coverage by 0.07%.
Report is 2 commits behind head on development.
The diff coverage is n/a.

Additional details and impacted files

@@               Coverage Diff               @@
##           development     #951      +/-   ##
===============================================
- Coverage        88.62%   88.56%   -0.07%     
===============================================
  Files              221      219       -2     
  Lines            13130    12405     -725     
===============================================
- Hits             11637    10986     -651     
+ Misses            1493     1419      -74     

see 96 files with indirect coverage changes

[jeffdiclemente]

Is it necessary to call set_property(TARGET ${us_configurationadmin_test_exe_name} PROPERTY INTERPROCEDURAL_OPTIMIZATION ${CMAKE_ENABLE_LTO}) in each CMakeLists.txt file? Can CMAKE_INTERPROCEDURAL_OPTIMIZATION be used to set this property once and have it used for all targets?