debug-manager: Remove weak pointer when needed
file-manager: Remove weak pointer when plugin is finalized
quick-open: Remove weak pointer on deactivation
run-program: Remove unneeded weak pointer
tools: Remove weak pointer when the context is destroyed
symbol-db: Remove weak pointer when plugin is destroyed
language-support-cpp-java: Remove a critical warning when Anjuta is closed
build-basic-autotools: Remove unused idle handler
project-manager: Fix bgo#723452 - Critical warnings when closing Anjuta window if multiple windows are open