Rename the cmQtAutomoc class to cmQtAutoGenerators.

It will be extended to process .ui and .qrc files too.
Rename the cmQtAutoGenerator instances to reflect coming features.
Rename the cmake_automoc command to cmake_autogen.

There is no need for a "cmake_automoc" backward compatibility command
because it is internal, undocumented, and only executed from a matching
version of cmake.
Move variable set to where it is used.
Rename local variable to reflect generic use.
Rename method to reflect generic use.
Rename some variables to reflect broader scope.
Add the AUTOGEN_TARGETS_FOLDER and obsolete AUTOMOC_TARGETS_FOLDER.
Move some makefile definitions up away from moc-specific code.
Rename the AutomocInfo.cmake file to be more generic.
Extract an SetupAutoMocTarget method.

This class will soon gain methods for autouic and autorcc.
Rename RunAutomoc to RunAutogen.

It will soon be used to process ui and rcc files too.
Update output messages for generic use.
Add extra checks for the AUTOMOC target property.

In an upcoming commit, this class will be used even if it is not set.
Rename the QtAutomoc tests to QtAutogen.
Run the main executable created in the autogen tests.

Don't try to show the windows, which would require a gui capable test
machine, and that's not guaranteed.

Automatically link to qtmain.a on Windows to avoid a policy warning. Set
policy CMP0020 to NEW by increasing the required version.

Don't attempt to run the test when using Windows.
Record which files are skipped by automoc.

They may not be skipped by autouic.
Add automatic uic invocation for Qt.

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.
Add automatic rcc invocation for Qt.

This replaces the need to invoke qt4_add_resources by allowing
adding the source .qrc file directly to the target sources.
CMakeDetermine*Compiler: Remove temporary cache entry

When the user or toolchain file sets CMAKE_<LANG>_COMPILER to a name
without a path we use find_program with CMAKE_<LANG>_COMPILER_WITH_PATH
to search for the tool.  Remove the temporary cache entry afterward to
avoid exposing it to projects.  It is not set by other logic paths so no
one should be using it.