Add loose parsing option for dates, accepting mixed case and missing delimiters

CHANGELOG.md

+## 0.12.1
+  * Adds a DateFormat.parseLoose that accepts mixed case and missing
+  delimiters when parsing dates. It also allows arbitrary amounts of
+  whitespace anywhere that whitespace is expected. So, for example,
+  in en-US locale a yMMMd format would accept "SEP 3   2014", even
+  though it would generate "Sep 3, 2014". This is fairly limited, and
+  its reliability in other locales is not known.
+
 ## 0.12.0+3
   * Update pubspec dependencies to allow analyzer version 23.
 
 ## 0.12.0+2
   * No user impacting changes. Tighten up a couple method signatures to specify
   that int is required.
 
 ## 0.12.0+1
   * Fixes bug with printing a percent or permille format with no fraction
   part and a number with no integer part. For example, print 0.12 with a
@@ skipping 109 matching lines @@
   canonicalizing. Previously anything of length > 6 was left completely alone.
 
 ## 0.9.8
 
 * Add a "meaning" optional parameter for Intl.message to distinguish between
   two messages with identical text.
 
 * Handle two different messages with the same text.
 
 * Allow complex string literals in arguments (e.g. multi-line)