The ElfImporter is not a real trace importer, but we locate it
into the import-trace utility, since here the infrastructure is
already in place to import things related to an elf binary into
the database.
The ElfImporter calls objdump and dissassembles an elf binary
and imports the results into the database.
Change-Id: I6e35673c8dbee3b7e8dfc7549d10e5dca9b55935