* Makefile.am (pinentry_qt4): New.
(SUBDIRS): Add pinentry_qt4.
* configure.ac: Add arg pinentry-qt4. Check for Qt4 libraries.
Substitute variables PINENTRY_QT4_CFLAGS, PINENTRY_QT4_LIBS,
PINENTRY_QT4_LDFLAGS, MOC4.
(BUILD_PINENTRY_QT4): New conditional.
(PINENTRY_QT4): New define.
* m4/qt.m4: Remove check for Qt4 libraries.
* m4/qt4.m4: New.
* qt4/Makefile.am: Check for BUILD_PINENTRY_QT4 instead of
BUILD_PINENTRY_QT.
(bin_PROGRAMS): Change pinentry-qt to pinentry-qt4.
(AM_CXXFLAGS): Change PINENTRY_QT_CFLAGS to PINENTRY_QT4_CFLAGS.
(pinentry_qt_LDADD): Renamed to pinentry_qt4_LDADD.
(pinentry_qt4_LDADD): Change PINENTRY_QT_LIBS to PINENTRY_QT4_LIBS.
(pinentry_qt_LDFLAGS): Renamed to pinentry_qt4_LDFLAGS.
(pinentry_qt4_LDFLAGS): Change PINENTRY_QT_LDFLAGS to
PINENTRY_QT4_LDFLAGS.
(pinentry_qt_SOURCES): Renamed to pinentry_qt4_SOURCES.
(nodist_pinentry_qt_SOURCES): Renamed to nodist_pinentry_qt4_SOURCES.
(.h.moc): Change MOC to MOC4.