configure: Add date with rev information

Date makes it even clearer that when was the last commit for the build
that one is running. Add this info alongwith rev. Change inspired by
rustc.

Before
```
$ suricata -V
This is Suricata version 5.0.0-dev (rev 2d217e666)
```

After
```
This is Suricata version 5.0.0-dev (2d217e666 2019-07-12)
```

Closes redmine ticket #3092

configure.ac

@@ -2468,6 +2468,8 @@ fi
         if test "$HAVE_GIT_CMD" != "no"; then
             if [ test -d .git ]; then
                 REVISION=`git rev-parse --short HEAD`
+                DATE=`git log -1 --date=short --pretty=format:%cd`
+                REVISION="$REVISION $DATE"
                 AC_DEFINE_UNQUOTED([REVISION],[${REVISION}],[Git revision])
             fi
         fi

src/suricata.c

@@ -581,7 +581,7 @@ static void SetBpfStringFromFile(char *filename)
 static void PrintUsage(const char *progname)
 {
 #ifdef REVISION
-    printf("%s %s (rev %s)\n", PROG_NAME, PROG_VER, xstr(REVISION));
+    printf("%s %s (%s)\n", PROG_NAME, PROG_VER, xstr(REVISION));
 #else
     printf("%s %s\n", PROG_NAME, PROG_VER);
 #endif
@@ -684,7 +684,7 @@ static void PrintBuildInfo(void)
     const char *tls = "pthread key";
 
 #ifdef REVISION
-    printf("This is %s version %s (rev %s)\n", PROG_NAME, PROG_VER, xstr(REVISION));
+    printf("This is %s version %s (%s)\n", PROG_NAME, PROG_VER, xstr(REVISION));
 #elif defined RELEASE
     printf("This is %s version %s RELEASE\n", PROG_NAME, PROG_VER);
 #else
@@ -1054,7 +1054,7 @@ static void SCInstanceInit(SCInstance *suri, const char *progname)
 static TmEcode PrintVersion(void)
 {
 #ifdef REVISION
-    printf("This is %s version %s (rev %s)\n", PROG_NAME, PROG_VER, xstr(REVISION));
+    printf("This is %s version %s (%s)\n", PROG_NAME, PROG_VER, xstr(REVISION));
 #elif defined RELEASE
     printf("This is %s version %s RELEASE\n", PROG_NAME, PROG_VER);
 #else
@@ -1067,7 +1067,7 @@ static TmEcode LogVersion(SCInstance *suri)
 {
     const char *mode = suri->system ? "SYSTEM" : "USER";
 #ifdef REVISION
-    SCLogNotice("This is %s version %s (rev %s) running in %s mode",
+    SCLogNotice("This is %s version %s (%s) running in %s mode",
             PROG_NAME, PROG_VER, xstr(REVISION), mode);
 #elif defined RELEASE
     SCLogNotice("This is %s version %s RELEASE running in %s mode",