Add information on setting up development environment, running tests and
generating documentation.
Also update .gitignore to list files that will be generated during
testing.
Signed-off-by: Lubomír Sedlář <lsedlar@redhat.com>
$ git pull --rebase upstream master
will work also when there are commits on master branch - it will
just rebase the changes seamlessly in opposite to git merge.
Moreover by using git pull --rebase we will save two calls of git.
