Add VID Pattern Validation to CI Builds

1.) Makes VID Pattern checks fatal error if we have a bad pattern in
source
2.) Adds an additional step the CI build process to acitvely verify all pattern
files in all branches (including any new pull requests)

The long in short of it is that we'll know if anyone tries to submit an
improperly formatted VID pattern to avoid corrupting master pattern file.
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.
Remove vendor id check from travis.yml
Add Check to Makefile.am
Merge pull request #3 from claudijd/vendor_id_validation

Add VID Pattern Validation to CI Builds
Added references to github repository in README, *.c and *.h
where appropriate.  Updated ChangeLog.
Change the bug-report string in AC_INIT from the ike-scan email address to the
github URL, and modify ike-scan.c and psk-crack.c to display a URL rather than
an email address.

Add references to the github repository in ike-backoff-patterns and
ike-vendor-ids.
Added support for ECP Diffie Hellman groups 19, 20 and 21.

The --dhgroup option now supports these additional groups, and will send
key exchange payloads in aggressive mode with lengths as specified in RFC 4753.
Use payload type 43 for IKEv2 Vendor ID payloads.
Add new ID types from RFCs 5996, RFC 5282, RFC 5114, and RFC 6467.
Minor change to Firewall-1 NGX vendor ID name.