Look for an env var to help find the MSP430 library

[DanielO]

As it says on the tin.

[dlbeer]

This is probably a good idea, but:

• There needs to be corresponding documentation added to the manual page.
• Memory allocation failure needs to be handled correctly.
• I'm not sure if asprintf is available on all platforms where mspdebug is used. In particular, I suspect it may be unavailable when compiling with MinGW, but I haven't had a chance to try.

If you could fix those up, I'd be happy to reconsider. Most platforms will limit the maximum size of a filename to something that could reasonably fit in a stack-allocated fixed-size buffer, so relying on that might help.

[DanielO]

OK, I've updated it to use a stack var and updated the man page. (sorry it took a while, I spaced and forgot :)

[dlbeer]

Ok, looks good -- thanks.