Updated Vagrant based development documentation to be more clear.

(Redmine issue: #7041)

Makefile

@@ -501,7 +501,7 @@ data-fetch-dbsnapshot: FORCE
 data-import-dbsnapshot: FORCE
 	@echo "\n$(GREEN)*** Importing latest production database dump ***$(NC)\n"
 
-	@sudo -u postgres pg_restore --verbose --format=d --dbname=mentat_main ./data/devsnapshot/main
+	@sudo -u postgres pg_restore --verbose --clean --if-exists --format=d --dbname=mentat_main ./data/devsnapshot/main
 	@sudo -u postgres psql mentat_main -c "COPY reports_events ($(cat /vagrant/data/devsnapshot/main/reports_events.cols)) FROM stdin;" < ./data/devsnapshot/chunks/reports_events.dat
 	@sudo -u postgres psql mentat_main -c "COPY statistics_events ($(cat /vagrant/data/devsnapshot/main/statistics_events.cols)) FROM stdin;" < ./data/devsnapshot/chunks/statistics_events.dat
 	@sudo -u postgres psql mentat_main -c "COPY changelogs_items ($(cat /vagrant/data/devsnapshot/main/changelogs_items.cols)) FROM stdin;" < ./data/devsnapshot/chunks/changelogs_items.dat

doc/sphinx/_doclib/development.rst

@@ -690,12 +690,24 @@ initial tips:
 
 .. code-block:: shell
 
+	# Alias to quickly sudo su to mentat system user
+	sm # Stands for 'sudoSuMentat'
+	# Alias to quickly sudo su to vagrant system user
+	sv # Stands for 'sudoSuVagrant'
 	# Alias to quickly enter work directory:
 	wd # Stands for 'WorkDirectory'
 	# Alias to enable Python virtual environment:
 	ve # Stands for 'VirtualEnvironment'
 
-Basically you should execute both of these aliases in succesion to end up with a prompt like this
+The ``mentat`` user is the system user preconfigured to run Mentat. The ``vagrant`` user is a system user that owns
+all project files. If you need to execute Mentat scripts and daemons, you should always switch to ``mentat``
+user. If you need to work with the files and Vagrant box, you should always switch to ``vagrant`` user.
+It is possible, that both of these user accounts will be merged in the future. However now the roles
+are kept separate, because the usage of ``mentat`` user mimics the environment on production and ``vagrant`` user
+is deeply baked into Vagrant and the change could be distruptive. By default by executing ``vagrant ssh``
+command you will be connected as vagrant user.
+
+Basically you should always execute ``ve`` alias to activate virtual environment and to end up with a prompt like this
 and be ready to work:
 
 .. code-block:: shell