autoreload added

[WuerfelDev]

some things about that: main.cpp#L861: This could be replaced with nodelay or removed. Not sure what is best

main.cpp#914: Since halfdelay is set, this is non-blocking and therefore currently only useful if typed at a speed of <0.1s per character

main.cpp#933: the inotify watch fires multiple times for a file change, we could act only after checking the content of the inotify event, the usleep is a little workaround to lower the risk of loading an incomplete document

main.cpp#936: Is there a fancier way of doing this?