Better injection service

[Kentzo]

• Following Find easier way to inject into app without menubar #16 this service should be easy to embed into applications without menu bar
• It should support both LLDB and GDB (Inject F-Script into application requires gdb #13) by check on known location (/usr/bin, /usr/bin/local), via xcodebuild or from the environment variable name FSCRIPT_DEBUGGER_PATH
• It should be part of the application so users won't need to install script manually. F-Script already provides some services that can be enabled in System Settings, like Execute Selection or Put Command. Inject F-Script should be among them.