Fixed: Allowed storing blank values in custom tag files. Keys still
required. This allows accommodating files that cannot be scanned for
viruses etc.
New: Added a unit test to check if tag files work well with Unicode
chars.
Fixed: A blank line in a custom tag file was being logged as a warning.
Removed its logging.
Fixed: No longer throws an NPE When a file is uploaded without an MD5.
Fixed: FidoParser now reads only the first line of output from Fido when
it returns multiple matches for a single file.
NEW: Added preservation of files by converting them to an "open file
format" using Xena java library. Files that can be converted will be
stored in .preserve folder within payload folder of bag. Tag file
preserve.txt maps the payload files to their corresponding
preserved-format file. Unconvertible files are identified with the value
'UNCONVERTIBLE' as value against the payload filepath.

NEW: Added PreservationCompleter that runs before DcStorageCompleter.
Changed: FileSummary object now includes String that contains filepath
to preserved file. BagSummaryTask populates those values.
Changed: The tomcat-maven-plugin version in DataCommons' Pom.
Changed: Refactored code in LdapPerson, LdapRequest and LdapRequestTest.
Changed: Allowed Bags Archive Folder to be blank. This disables archive
functionality of DcStorage. Useful for development environments to save
space.
Changed: On deleting preserved files (payload files in data/.preserve)
the parent folder of that file is checked for other files. If no other
files are present, that folder is deleted.
Merge branch 'feat/file-preserve' into dev
FIXED: Excluded Commons Logging from all dependencies. This should
prevent SLF4J from using Commons Logging Jars instead of Log4j

NEW: Added AccessDeniedExceptionMapper class that logs only the message
of AccessDeniedException instead of the full stack trace.

FIXED: Moved code from HtmlListProvider, HtmlStringProvider,
TextListProvider into the ExceptionMappers that used the code so it
didn't result in all HTTP responses with entity String being wrapped in
an HTML error page, which caused issues with Python uploader and
DcClient that don't expect Html responses.
CHANGED: Reduced excessive logging. Included relevant information such
as username and other parameters (if applicable) in logging messages.
Merge remote-tracking branch 'origin/master'