Trigger minidumps on lua crashes.

1. Kills many pokemon try/catches.
2. Add exception field to virgo on lua crash when we get an exception from the top pcall.  Unfortunately, its difficult to pass in the exception string to google breakpad hence the global variable. Also, we can now call breakpad to make a minidump without segfaulting.
3. Adds a lua stacktrace to the run time stderr printer for better userfeedback.
Only send report with special startup flag.

The agent now requires a --report-lua-crash to minidump after a lua crash.  This shouldn't be enabled by default for debuging, hence adding it to the packages.