release task: update version and changes.h

Author: tjhei

VERSION

@@ -1 +1 @@
-1.4.0-pre
+1.5.0-pre

doc/manual/manual.tex

@@ -123,7 +123,7 @@
 \hfill{\Huge \fontfamily{\sfdefault}\selectfont User Manual \\
 \raggedleft \huge \fontfamily{\sfdefault}\selectfont Version
 % keep the following line as is so that we can replace this using a script:
-1.4.0-pre %VERSION-INFO%
+1.5.0-pre %VERSION-INFO%
 \\\large(generated \today)\\}
 
 %AUTHOR(S) & WEBSITE%