Add development makefile. Update changelog. Add release notes for version 2.1.2

Makefile

@@ -0,0 +1,113 @@
+.PHONY: clean-pyc clean-build
+
+define BROWSER_PYSCRIPT
+import sys, webbrowser
+webbrowser.open(sys.argv[1])
+endef
+export BROWSER_PYSCRIPT
+BROWSER := python -c "$$BROWSER_PYSCRIPT"
+
+
+help:
+	@echo
+	@echo "clean-build - Remove build artifacts."
+	@echo "clean-pyc - Remove Python artifacts."
+	@echo "clean - Remove Python and build artifacts."
+
+	@echo "test MODULE=<python module name> - Run tests for a single App, module or test class."
+	@echo "test-all - Run all tests."
+	@echo "docs_serve - Run the livehtml documentation generator."
+
+	@echo "translations_make - Refresh all translation files."
+	@echo "translations_compile - Compile all translation files."
+	@echo "translations_push - Upload all translation files to Transifex."
+	@echo "translations_pull - Download all translation files from Transifex."
+
+	@echo "requirements_dev - Install development requirements."
+	@echo "requirements_docs - Install documentation requirements."
+	@echo "requirements_testing - Install testing requirements."
+
+	@echo "sdist - Build the source distribution package."
+	@echo "wheel - Build the wheel distribution package."
+	@echo "release - Package (sdist and wheel) and upload a release."
+
+	@echo "runserver - Run the development server."
+
+
+# Cleaning
+
+clean: clean-build clean-pyc
+
+clean-build:
+	rm -fr build/
+	rm -fr dist/
+	rm -fr *.egg-info
+
+clean-pyc:
+	find . -name '*.pyc' -exec rm -f {} +
+	find . -name '*.pyo' -exec rm -f {} +
+	find . -name '*~' -exec rm -f {} +
+
+
+# Testing
+
+test:
+	./manage.py test $(MODULE) --settings=mayan.settings.testing --nomigrations
+
+test-all:
+	./manage.py runtests --settings=mayan.settings.testing --nomigrations
+
+
+# Documentation
+
+docs_serve:
+	$(BROWSER) http://127.0.0.1:8000
+	cd docs;make livehtml
+
+
+# Translations
+
+translations_make:
+	contrib/scripts/process_messages.py -m
+
+translations_compile:
+	contrib/scripts/process_messages.py -c
+
+translations_push:
+	tx push -s
+
+translations_pull:
+	tx pull
+
+
+# Requirements
+
+requirements_dev:
+	pip install -r requirements/development.txt
+
+requirements_docs:
+	pip install -r requirements/documentation.txt
+
+requirements_testing:
+	pip install -r requirements/testing.txt
+
+
+# Releases
+
+release: clean
+	python setup.py sdist bdist_wheel upload
+
+sdist: clean
+	python setup.py sdist
+	ls -l dist
+
+wheel: clean
+	python setup.py bdist_wheel
+	ls -l dist
+
+
+# Dev server
+
+runserver:
+	$(BROWSER) http://127.0.0.1:8000
+	./manage.py runserver