new version number for release 4.8.0
update po/pot files
Merge branch 'master' into v4.8.x
updated spanish, ukranian, and dutch translation
Merge branch 'master' into v4.8.x
update NEWS file
only enable osxapp build target on apple systems, clean up configure.ac a tiny bit
remove experimental from gtk build option
fix osxapp enable option in configure.ac
updated Changelog, DIFFSTAT, and SHORTLOG
make all tests for strings in configure use the same scheme
Merge branch 'master' into v4.8.x
USE OSXAPP instead of APPLE and fix withval->enableval in AC_ARG_ENABLE
fix typo and prefix

AC_PREFIX_DEFAULT was always set, even if AS_IF didn't get called? Some kind of caching?
Using just prefix=... seems to work though
forget a few __APPLE__ ifdefs; changed to OSXAPP
updated NEWS
updated ChangeLog, DIFFSTAT and SHORTLOG
line numbers in PO got updated