Upgraded version number to reflect correct treatment of hydro in multi-dt and...

Upgraded version number to reflect correct treatment of hydro in multi-dt and MPI as well as the inclusion of star particles.

configure.ac

@@ -16,7 +16,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 # Init the project.
-AC_INIT([SWIFT],[0.4.0],[https://gitlab.cosma.dur.ac.uk/swift/swiftsim])
+AC_INIT([SWIFT],[0.5.0],[https://gitlab.cosma.dur.ac.uk/swift/swiftsim])
 swift_config_flags="$*"
 
 #  Need to define this, instead of using fifth argument of AC_INIT, until 2.64.