Reloading binary/folder should also reload gdb’s window

**Is your feature request related to a problem? Please describe.**
Since gdbgui is separate from my code editor, I let it run while rebuilding. Then I want to debug something else so I hit:
1) The "load binary" button
1) The "load file" button
1) Since because of #499 I used the gdb window, I also had to send it the `directory` command (just discovered it)

**Describe the solution you'd like**
I would love if one of the button reloaded everything.
Maybe gdbgui could auto-reload (or open a popup to ask the user if it should) when inotify signal a fs change

**Describe alternatives you've considered**
Clicking 2 buttons, re opening the files (rust experience is not optimal), AND telling gdb about the change.