Add getMonthRegexByLocale

I am Korean, and live in Seoul. Korea
I use Korean

I cloned logback.
and run "mvn test".

Failed ....

month(ch.qos.logback.core.util.DatePatternToRegexTest)  Time elapsed: 0 sec <<< FAILURE!
java.lang.AssertionError: [2009-9월-03] does not match regex [\d{4}-.{3,12}-\d{2}]
	at org.junit.Assert.fail(Assert.java:93)
	at org.junit.Assert.assertTrue(Assert.java:43)
	at ch.qos.logback.core.util.DatePatternToRegexTest.verify(DatePatternToRegexTest.java:105)
	at ch.qos.logback.core.util.DatePatternToRegexTest.doTest(DatePatternToRegexTest.java:89)
	at ch.qos.logback.core.util.DatePatternToRegexTest.doTest(DatePatternToRegexTest.java:93)
	at ch.qos.logback.core.util.DatePatternToRegexTest.month(DatePatternToRegexTest.java:56)
...

dot(ch.qos.logback.core.util.DatePatternToRegexTest)  Time elapsed: 0 sec <<< FAILURE!
java.lang.AssertionError: [2009.9월.03] does not match regex [\d{4}\..{3,12}\.\d{2}]
	at org.junit.Assert.fail(Assert.java:93)
	at org.junit.Assert.assertTrue(Assert.java:43)
	at ch.qos.logback.core.util.DatePatternToRegexTest.verify(DatePatternToRegexTest.java:105)
	at ch.qos.logback.core.util.DatePatternToRegexTest.doTest(DatePatternToRegexTest.java:89)
	at ch.qos.logback.core.util.DatePatternToRegexTest.doTest(DatePatternToRegexTest.java:93)
	at ch.qos.logback.core.util.DatePatternToRegexTest.dot(DatePatternToRegexTest.java:62)
...

timeZone(ch.qos.logback.core.util.DatePatternToRegexTest)  Time elapsed: 0 sec  <<< FAILURE!
java.lang.AssertionError: [2009-9월-03 21:57:16 KST] does not match regex [\d{4}-.{3,12}-\d{2} \d{2}:\d{2}:\d{2} .*]
	at org.junit.Assert.fail(Assert.java:93)
	at org.junit.Assert.assertTrue(Assert.java:43)
	at ch.qos.logback.core.util.DatePatternToRegexTest.verify(DatePatternToRegexTest.java:105)
	at ch.qos.logback.core.util.DatePatternToRegexTest.doTest(DatePatternToRegexTest.java:89)
	at ch.qos.logback.core.util.DatePatternToRegexTest.doTest(DatePatternToRegexTest.java:93)
	at ch.qos.logback.core.util.DatePatternToRegexTest.timeZone(DatePatternToRegexTest.java:68)
...

dayInWeek(ch.qos.logback.core.util.DatePatternToRegexTest)  Time elapsed: 0 sec  <<< FAILURE!
java.lang.AssertionError: [2009-9월-목] does not match regex [\d{4}-.{2,4}-.{2,12}]
	at org.junit.Assert.fail(Assert.java:93)
	at org.junit.Assert.assertTrue(Assert.java:43)
	at ch.qos.logback.core.util.DatePatternToRegexTest.verify(DatePatternToRegexTest.java:105)
	at ch.qos.logback.core.util.DatePatternToRegexTest.doTest(DatePatternToRegexTest.java:89)
	at ch.qos.logback.core.util.DatePatternToRegexTest.doTest(DatePatternToRegexTest.java:93)
	at ch.qos.logback.core.util.DatePatternToRegexTest.dayInWeek(DatePatternToRegexTest.java:74)
...


Some of Country have Different size of Month Regex.

E.g. Korean.

Calendar cal = Calendar.getInstance();
cal.set(2009, 8, 3, 21, 57, 16);

SimpleDateFormat sdf = new SimpleDateFormat("MMM", locale.KOREAN);
String sMonth = sdf.format(cal.getTime());
sMonth is "9월" , sMonth.lenth() is 2

getMonthRegexByLocale return valid Regex (Each country).

And

Week(E) is some.

so I edited.

    case 'E':
      if (occurrences <= 3) {
        return ".{1,8}";
      }
      return ".{3,12}";

check Jira's http://jira.qos.ch/browse/LOGBACK-969 sampleFiles....