modules: added MAGNUM_BINARY_INSTALL_DIR variable to FindMagnum.cmake.

Will be used in depending projects for e.g. installing DLLs on Windows.

modules/FindMagnum.cmake

@@ -96,6 +96,7 @@
 #  MAGNUM_*_LIBRARY             - Component libraries (w/o dependencies)
 #  MAGNUM_*_LIBRARY_DEBUG       - Debug version of given library, if found
 #  MAGNUM_*_LIBRARY_RELEASE     - Release version of given library, if found
+#  MAGNUM_BINARY_INSTALL_DIR    - Binary installation directory
 #  MAGNUM_LIBRARY_INSTALL_DIR   - Library installation directory
 #  MAGNUM_PLUGINS_[DEBUG|RELEASE]_INSTALL_DIR - Plugin installation directory
 #  MAGNUM_PLUGINS_FONT_[DEBUG|RELEASE]_INSTALL_DIR - Font plugin installation
@@ -460,6 +461,7 @@ find_package_handle_standard_args(Magnum
 
 # Installation dirs
 include(CorradeLibSuffix)
+set(MAGNUM_BINARY_INSTALL_DIR ${CMAKE_INSTALL_PREFIX}/bin)
 set(MAGNUM_LIBRARY_INSTALL_DIR ${CMAKE_INSTALL_PREFIX}/lib${LIB_SUFFIX})
 set(MAGNUM_PLUGINS_DEBUG_INSTALL_DIR ${MAGNUM_LIBRARY_INSTALL_DIR}/magnum-d)
 set(MAGNUM_PLUGINS_RELEASE_INSTALL_DIR ${MAGNUM_LIBRARY_INSTALL_DIR}/magnum)
@@ -481,6 +483,7 @@ mark_as_advanced(FORCE
     MAGNUM_LIBRARY_RELEASE
     MAGNUM_LIBRARY
     MAGNUM_INCLUDE_DIR
+    MAGNUM_BINARY_INSTALL_DIR
     MAGNUM_LIBRARY_INSTALL_DIR
     MAGNUM_PLUGINS_DEBUG_INSTALL_DIR
     MAGNUM_PLUGINS_RELEASE_INSTALL_DIR