initial 4.5 merge
initial 4.5 merge: autoconf
4.5 merge #2
4.5 merge #2: autoconf
4.5 merge #3
4.5 merge #4
4.5 merge #4: autoconf
4.5 merge #4: more autoconf
4.5 merge #5
4.5 merge #5 autoconf
4.5 merge #6
Merge commit 'd7a8dbc' into develop: meta only