Drop Swiften dependency from backends

CMakeLists.txt

@@ -40,7 +40,7 @@ option(ENABLE_PURPLE "Build Libpurple plugin" ON)
 option(ENABLE_SMSTOOLS3 "Build SMSTools3 plugin" ON)
 option(ENABLE_XMPP "Build XMPP plugin" ON)
 option(ENABLE_WEBUI "Build Web UI" ON)
-
+option(ENABLE_SLACK_FRONTEND "Build Slack frontend" OFF)
 option(ENABLE_DOCS "Build Docs" ON)
 # option(ENABLE_LOG "Build with logging using Log4cxx" ON)
 option(ENABLE_TESTS "Build Tests using CppUnit" OFF)
@@ -98,6 +98,8 @@ if(WIN32)
 	link_directories("$ENV{CMAKE_PREFIX_PATH}/lib")
 endif(WIN32)
 
+find_package( Threads )
+
 set(Boost_FIND_QUIETLY ON)
 find_package(Boost COMPONENTS program_options date_time system filesystem regex thread locale REQUIRED)
 

backends/frotz/CMakeLists.txt

@@ -5,6 +5,6 @@ file(GLOB SRC *.c *.cpp)
 add_executable(spectrum2_frotz_backend ${SRC})
 
 
-target_link_libraries(spectrum2_frotz_backend transport pthread ${Boost_LIBRARIES} ${SWIFTEN_LIBRARY} ${LOG4CXX_LIBRARIES})
+target_link_libraries(spectrum2_frotz_backend transport ${Boost_LIBRARIES} ${LOG4CXX_LIBRARIES})
 
 install(TARGETS spectrum2_frotz_backend RUNTIME DESTINATION ${CMAKE_INSTALL_LIBEXECDIR})