Don't store a mapping of the directory to the ui file. The directory
will be a unique key, allowing only one ui file to be specified.
Use the source file name instead as the mapping key.
Transitively consume the property from linked dependents.
Implement configuration-specific support by following the pattern
set out for compile definitions and includes in cmQtAutoGenerators.
Implement support for origin-tracking with CMAKE_DEBUG_TARGET_PROPERTIES.
This is motivated by the needs of KDE, which provides a separate
translation system based on gettext instead of the Qt linguist
translation system. The Qt uic tool provides command line options
for configuring the method used to translate text, and to add an
include directive to the generated file to provide the method.
http://thread.gmane.org/gmane.comp.kde.devel.frameworks/7930/focus=7992
Implement the interface to provide the uic options as a usage-requirement
on the KI18n target, as designed for KDE.
The source files are already processed by cmQtAutomoc to look for
moc includes, so extend that to also look for ui_ includes and
find corresponding .ui files to process.
This replaces the need to invoke qt4_wrap_ui().
As the ui files are not likely to be part of the SOURCES of the
target, store the options associated with them separately in the
cmMakefile for querying during the autogen run.