syslog-ng-ctl: move into a separate subdirectory

Instead of sharing a home with the main syslog-ng binary, use a separate,
dedicated folder.

Signed-off-by: Balazs Scheidler <bazsi@balabit.hu>
.travis.yml: Test the merge/ prefixed branches on Travis CI too

Signed-off-by: Gergely Nagy <algernon@balabit.hu>
Bump the @version pragmas to 3.6

Since the default version was switched to 3.6 earlier, bump the @version
of the default config and the in the func-tests too.

Signed-off-by: Gergely Nagy <algernon@balabit.hu>
README.md: add new file to describe syslog-ng


Signed-off-by: Balazs Scheidler <bazsi@balabit.hu>
.travis.yml: Install sqlite3 and libdbd-sqlite3 too

In order to run the SQL func tests, install sqlite3 and libdbd-sqlite3
too.

Signed-off-by: Gergely Nagy <algernon@balabit.hu>