depload is a small plugin for IDA 6.3 (probably others)
which crawls through the import table and loads up all the
files that it depends on. It can also load up an unrelated file
specifically. If you really want, you can keep running the
plugin and it will recurse through and get dependencies
for the dependencies.
After the new file is loaded up, a repeatable comment is placed to point any call to an external function, to go right to the code itself!
Currently it's Windows specific as it looks for '\' based paths and not '/' based paths. This probably would take 30 seconds to change.