Make collator name things appropriately for IPC tests

This way we can differentiate between, say, the basic test, and the
basic test run under e10s ('basic' vs. 'basic.ipc').
Replace dots in suite name with underscores.

This gives us cleaner (in my opinion) file names.

I've also added a nice comment about why we're modifying the filename
the way we are to get the suite name. Hopefully it will be enlightening
for those that come after me.
Add support for logging to stderr

This lets me more easily test things without having to tail logs all the
time. Hooray!
Disable necko IPC security checks

This is necessary because we don't have a docshell, which is what is
responsible for sending the security info, and without the security info
(or the checks disabled), IPDL will barf at us.
Add basic IPC test