git: MANIFEST, build, *.egg in gitignore

* Removes `MANIFEST` from gitignore.

* Adds `build` and `*.egg` to gitignore.

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
setup: removal of `requirements.pip`

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
docs: removal of unnecessary `make.bat`

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
setup: initial release of `CHANGES`

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
setup: `run_tests.sh` -> `run-tests.sh`

* Renames `run_tests.sh` to `run-tests.sh` for the overall consistency
  with our other Python packages.

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
setup: initial release of `MANIFEST.in`

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
global: uniform licence headers in source files

* Adds header containing licence information to each source file.

* Amends copyright holders and copyright years for every source file
  based on its git commit log history.

* Adds `AUTHORS` file.

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
docs: richer documentation

* Adds information about changes, licence, and authors to the
  documentation.

* Adds Travis CI and Coveralls badges to the documentation.

* Cleans the wording of the tutorial, renames and reorders sections,
  removes unnecessary links.

* Fixes typo in `dictdiffer.patch()` docstring.

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>
setup: Trove classifiers

* Adds Trove classifiers according to PEP 301.

* Capitalises the project name to "Dictdiffer" in consistency with the
  documentation.

* Uses "Invenio Collaboration" as the current maintainer.

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>