Add Make Check Output to gitignore
Add Make Check for Vendor ID Patterns

1.) Adds a handful of items to .gitignore that are generated with 'make
check' so they don't get checked into source.
2.) Reverts recent change of WARN -> ERR back to WARN on pattern
failures in ike-scan.c.  This is to avoid having other checks that use
vid-patterns from failing, which makes it less straight forward when we
have pattern failures.
3.) Adds a make check to alert when patterns file contains an pattern
that cannot be parsed.