rdmd configuration files

[Jonathan Marler via Digitalmars-d]

The use case is you have a collection of D scripts within the 
same directory subtree (maybe a git repo) that all share some 
common configuration. Maybe they all require extra search paths 
to find source/libraries, or they all throw exceptions to the 
user and should be compiled with debug symbols so exceptions 
print their full stacktrace, etc.  Rather then requiring the user 
to call the script in a particular way or wrapping all the 
scripts with yet another tool, what about adding support in rdmd 
for configuration files?  The configuration file could live in 
any parent directory of the script being ran:

FileSystem:
   /a/b/c/myscript.d

Shell:
/a/b/c> rdmd myscript.d

rdmd checks for /a/b/c/rdmd.config
rdmd checks for /a/b/rdmd.config
rdmd checks for /a/rdmd.config
rdmd checks for /rdmd.config

The rdmd.config file would apply to all rdmd scripts in all 
subdirectories on the file system.  It works similar to how git 
determines whether or not it lives in a repository (searches all 
parent directories for the .git directory).

Additionally, allowing rdmd to be configured through files makes 
more complicated configurations more reasonable.  For example, if 
your scripts depend on a dub package, you could do this easily in 
a configuration file, whereas doing this on the command line 
would be a nightmare.

Supporting this type of configuration could easily be implemented 
in a wrapper around rdmd (rdmdc?), however, if this idea is 
generally useful then it should be added to rdmd itself so 
everyone benefits.  The question is, is this feature general and 
useful enough to justify adding to rdmd itself, or is this only 
useful in rare cases meaning it should live inside an rdmd 
wrapper?