Feature Request: support devenv macros in Environment setting

[benoit-germain]

I have a solution where I build a Lua module DLL for several versions of the language. Each version is built into a specific folder where the interpreter is located. Each configuration of the project has a name that is specific to the Lua version it targets (Debug 5.1, Release 5.4, ...). Each interpreter is found in a folder that matches the configuration name, and the module DLL is built in these folders as well.

However, the corresponding unit tests executable's working directory has to be the same for all versions (a folder where the test scripts can be found). In order for it to be able to locate the module, I need to tell it where to look. I've tried the following:

		<Environment>
			<LUA_PATH>$(SolutionDir)/_LuaVersions/$(PlatformName)/$(ConfigurationName)</LUA_PATH>
			<LUA_CPATH>$(SolutionDir)/_LuaVersions/$(PlatformName)/$(ConfigurationName)</LUA_CPATH>
		</Environment>

but apparently the devenv macros ($(SolutionDir), etc) are not expanded, which results in the environment variables LUA_PATH and LUA_CPATH to contain the above text verbatim. What about changing that :-) ?