Bug 977: -T / --init-errors-fatal to process all rules

[inliniac]

Have -T / --init-errors-fatal process all rules so that it's easier
to debug problems in ruleset. Otherwise it can be a lengthy fix, test
error cycle if multiple rules have issues.

Convert empty rulefile error into a warning.

Bug #977

[duanehoward]

Looks like it works for empty file:

[17308] 21/11/2014 -- 18:21:44 - (detect.c:410) (SigLoadSignatures) -- [ERRCODE: SC_ERR_NO_RULES(42)] - No rules loaded from /etc/suricata/rules/empty.rules
[17308] 21/11/2014 -- 18:21:44 - (detect.c:439) (SigLoadSignatures) -- 12 rule files processed. 9994 rules successfully loaded, 0 rules failed

[17308] 21/11/2014 -- 18:21:52 - (suricata.c:2293) (main) -- Configuration provided was successfully loaded. Exiting.

Also appears to work for multiple broken rules:
[22071] 21/11/2014 -- 18:26:33 - (util-rule-vars.c:89) (SCRuleVarsGetConfVar) -- [ERRCODE: SC_ERR_UNDEFINED_VAR(101)] - Variable "HME_NET" is not defined in configuration file
[22071] 21/11/2014 -- 18:26:33 - (detect.c:354) (DetectLoadSigFile) -- [ERRCODE: SC_ERR_INVALID_SIGNATURE(39)] - error parsing signature "alert tcp $HME_NET any -> $EXTERNAL_NET any (msg:"BROKEN RULE 1"; flow:established; content:"|52 61 72 21 1A 07 00|"; tag:session,300,seconds; classtype:misc-activity; sid:6999998; rev:1;)" from file /etc/suricata/rules/empty.rules at line 1
[22071] 21/11/2014 -- 18:26:33 - (detect-content.c:204) (DetectContentDataParse) -- [ERRCODE: SC_ERR_INVALID_SIGNATURE(39)] - Invalid hex code assembly in content - "|52 61 72 21 1A 07 00". Invalidating signature
[22071] 21/11/2014 -- 18:26:33 - (detect.c:354) (DetectLoadSigFile) -- [ERRCODE: SC_ERR_INVALID_SIGNATURE(39)] - error parsing signature "alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"BROKEN RULE 2"; flow:established; content:"|52 61 72 21 1A 07 00"; tag:session,300,seconds; classtype:misc-activity; sid:6999999; rev:6;)" from file /etc/suricata/rules/empty.rules at line 2
[22071] 21/11/2014 -- 18:26:33 - (detect.c:439) (SigLoadSignatures) -- 12 rule files processed. 9994 rules successfully loaded, 2 rules failed

My only concern is that the final exit code is still 0, indicating success, where previously it would exit with a failure. Using -T to test loads before a Suricata restart would currently only require checking the final exit code of suricata -T, this change seems like it will break that though.

[inliniac]

Thanks for testing @duanehoward, fixed up in #1225