Let the D compiler print the dependencies and pragma(lib,...).

[Frank Benoit (keinfarbton)]

To make any build tool completely independent from parsing the source
files, please print out the pragma( lib ) also.

I think, that this again shall be in the compiler, because this is also
dependent in evaluation of version and debug conditions. Implementing
this redundant into the build tools does not make sense.

To make the command line switches more easy, we can do all with one
switch and use the same format on stdout or the file.

-bldinfo
-bldinfo=filename
Prints the dependencies and the needed libs to stdout or [filename].
Output can look like this:
module imp: my.module => my.other.module
module imp: my.module => std.string
module imp: my.module => std.file
module lnk: my.module => mynativelib.dll
module lnk: my.module => mynativelib2.dll

What do you think? Is there something else missing?