more i18n fixes, this time removing a hack that broke i18n in bundles, and also only...

more i18n fixes, this time removing a hack that broke i18n in bundles, and also only initializing NLS stuff if ENABLE_NLS is in effect. note that if translations are disabled by the user, we set the localedir used to look for message catalogs to a dir that is assumed to not exist (/this/cannot/exist) which should block all translation from happening.

git-svn-id: svn://localhost/ardour2/branches/3.0@13975 d708f5d6-7413-0410-9779-e7cbd77b26cf