Make it possible to 'compile' kdesrc-build without KDE installed.

It's a bit of a chicken and egg problem, otherwise. Well, of course one
can use kdesrc-build uninstalled, but this way an automated build host
can just start with "./kdesrc-build/kdesrc-build kdesrc-build" to ensure
it's up-to-date :-)

CMakeLists.txt

@@ -1,12 +1,16 @@
 cmake_minimum_required(VERSION 2.6) # Pretty much nothing works without this
 project(kdesrc-build)
 
-find_package(KDE4 REQUIRED) # Needed for the docs
+find_package(KDE4) # Needed for the docs, but optional.
 
-include(KDE4Defaults)
-include(MacroLibrary)
-
-macro_optional_add_subdirectory(doc)
+if (KDE4_FOUND)
+  include(KDE4Defaults)
+  include(MacroLibrary)
+  macro_optional_add_subdirectory(doc)
+else()
+   set(DATA_INSTALL_DIR  "${CMAKE_INSTALL_PREFIX}/apps" CACHE PATH "The parent directory where applications can install their data")
+   set(BIN_INSTALL_DIR   "${CMAKE_INSTALL_PREFIX}/bin"  CACHE PATH "The install dir for executables")
+endif()
 
 install(PROGRAMS ${CMAKE_CURRENT_SOURCE_DIR}/kdesrc-build DESTINATION ${BIN_INSTALL_DIR})
 install(FILES kdesrc-buildrc.xml DESTINATION ${DATA_INSTALL_DIR}/katepart/syntax)