Code for managing Wikimedia Foundation dump files

There are several types of dump files provided: full dumps,
dumps of current versions, and incremental (daily) dumps.
The are found online and (after being downloaded once), also
locally. The class MediaWikiDumpFile represents such a dump
and provides transparent access to its contents (whereever
it comes from, whatever type it is).

The WmfDumpFileManager provides methods for creating
MediaWikiDumpFile objects from the data seen online or in local
files. Classes that implement the interface DumpFileProcessor
can ask WmfDumpFileManager to call them for all relevant dump
files in the right order. This is the preferred way of processing
all dumps.

There are no tests yet. Testing will require suitable mock objects
to simulate the Web and the file systems. The code provides places
to inject these mock objects.

This contributes to issue #8.
Update .gitignore to ignore dumfile download directory

Also, the directory src/local/ is now ignored, so you can put
local experimental code there.
New mock classes for file and web access

This prepares test creation for the main classes in this package.
Assume UTF-8 encoding in all file/URL access classes
Tests for dump file management

* Extensive code for mocking Web and file access
* Use Mockito to mock BufferedReaders etc.
* Auxiliary resource files to use for mocking
* Actual tests
* Some simplifications in file structures
Move dump file type enum to separate file
Updated files to incorporate review comments

* Changes in documentation style.
* Some additional string constants.
* Bundled code to define file and directory names for dumps in
WmfDumpFile.
Tiny renaming according to style conventions.
Merge pull request #26 from Wikidata/dumpfile-provider

Dumpfile provider
Merge remote-tracking branch 'origin/master' into jsonToDataModel

Conflicts:
	wdtk-dumpfiles/pom.xml
	
	Should be fine.