Add CMake flag for keytests and disable by default

The keytests were previously enabled by default if the necessary
dependencies were found. They require a GUI and mouse so can
sometimes be annoying. Further, they are not currently reliable.
They are thus now disabled by default.

CMakeLists.txt

@@ -139,6 +139,7 @@ LYX_OPTION(INSTALL_PREFIX   "Install path for LyX" OFF ALL)
 LYX_OPTION(BUNDLE           "Build bundle  (experimental) " OFF ALL)
 LYX_OPTION(ENABLE_URLTESTS  "Enable for URL tests" OFF ALL)
 LYX_OPTION(ENABLE_EXPORT_TESTS "Enable for export tests" OFF ALL)
+LYX_OPTION(ENABLE_KEYTESTS  "Enable for keytests" OFF ALL)
 LYX_OPTION(ASAN             "Use address sanitizer" OFF ALL)
 LYX_COMBO(USE_QT            "Use Qt version as frontend" QT4 QT5)
 #LYX_OPTION(3RDPARTY_BUILD   "Build 3rdparty libs" OFF ALL)

development/autotests/CMakeLists.txt

@@ -67,7 +67,7 @@ if(QT_USES_X11)
     message(STATUS "cmake build is therefore omitting keytests")
   endif()
 
-  if(Missing)
+  if(Missing OR NOT LYX_ENABLE_KEYTESTS)
     set(_runtest FALSE)
   else()
     project(keytest)

lib/doc/Development.lyx

@@ -4732,7 +4732,18 @@ Keytests
 \end_layout
 
 \begin_layout Standard
-Automated tests based on the "MonKey Testing" keytest program.
+Automated tests based on the "MonKey Testing" keytest program are enabled
+ if the necessary dependencies are found and if the CMake flag 
+\begin_inset Flex Code
+status collapsed
+
+\begin_layout Plain Layout
+-DLYX_ENABLE_KEYTESTS=ON
+\end_layout
+
+\end_inset
+
+ is used.
  They are documented in the README document in 
 \begin_inset Flex Code
 status collapsed