* test suite fixes for link=static default
* emscripten renovation
* inherit from clang toolset
* update for 'new' fastcomp backend
* exceptions support
* dynamic linking support
* pthread support
* run-tests launcher via nodejs
Various restructure of test framework handling of paths to avoid duplicate path editing which caused failed tests. Adjust many tests to deal with added subdirectories in build outputs now that toolset requirements are active.