* Make the library modular usable.
* Switch to library requirements instead of source. As source puts extra source in install targets.
* Add wave tool build to all target.
* Add missing NO_LIB usage requirements.
* Add requires-b2 check to top-level build file.
* Bump B2 require to 5.2
* Change all <source> references to <library>.
* Move inter-lib dependencies to a project variable and into the build targets.
* Update build deps.
filesystem paths in MSVC are based on wchar_t so my 8b regex (and
std::string) were a problem for matching against native paths. Trying
again with the generic std::string interface to see if it works.
