Do not distribute Qt meta object files.

See bug #21526


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@24271 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
When freeciv-ruledit fails to load a ruleset, show correct ruleset name
in the error message.

See bug #21537


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@24274 a0f10bec-cc02-0410-94fc-a9cfff90b4cd
Fixed make target 'clean' of Windows installer building Makefile.

See bug #21529


git-svn-id: svn://svn.gna.org/svn/freeciv/trunk@24275 a0f10bec-cc02-0410-94fc-a9cfff90b4cd