* Work in progress to be able to invoke VS from within code.

* First pass at windows version of refactor of OSProcessSpawner

* Closer to getting VS path lookup working.

* Make OSString assignable/ctor able

* Work out program files directory directly, so don't have to expand %%.

* WIP: Improve handling of process spawning.

* Add support for splitting input by line.

* * Correctly locates visual studio install
* Added functionality to invoke vs via cmd

* Add option to execute the command line.

* Handle in ProcessUtil for windows -> WinHandle.

* Rename files slang-win-visual-studio-util.cpp/.h and slang-process-util.h

* First pass at unix/linux version of ProcessUtil.

* Fix reading Visual Studio path from the registry.

* Get compiling on linux with.

* Fix vcvarsall.bat name

* Use ProcessUtil to execute external code.

* Remove OSProcessSpawner.

* Remove includes for "os.h" where no longer needed.

* Fix tabbing issue in premake5.lua
Remove test code from slang-test-main.cpp

* Fix premake4.lua tabbing issue.

* Small fixes to slang-process-util.h
Init ExecuteResult on Win execute.

* Improve comments.

* Fix bug in StringUtil::calcLines - with oddly terminated source input being able to read past end.
Make slang-generate use StringUtil over it's own impl.

* Fix off by one bug in working out Visual Studio version.

* Fix bug in calculating Visual Studio Version

* Fix compilation on linux with string parameter being passed to messageFormat.

* Remove erroneous use of kOSError codes - use Result.

* First effort to generate standard compiler options.

* Initial efforts in compiling source code in test framework for VisualStudio.

* Testing compiling c code on VisualStudio on Windows.

* Fix warning on linux.

* Fix clang on linux warning (and therefore failing) returning a StringBuilder as String.

* Disable return-std-move on clang.

* CommandLine arguments are now tagged if they are escaped or not. That it is the clients responsibility to escape command lines that cannot be automatically escaped.

* Add checks on unix/linux that command line args are all unescaped.

* WIP getting runtime GCC to work.

* First pass compiler working on unix-like targets.

* Added File::remove function.

* Enable c-compile.c test on 'smoke'.

* WIP abstracting the CPP compiler concept.

* CPPCompilerSet and CPPCompilerUtil working on windows. Problem on unix.

* Used stdError for parsing of invoke of compiler to figure out verison.

* Removed some code that was no longer needed from slang-cpp-compiler.cpp