The standard Linux text editor implementation in Go
Current implementation is based on the source code from
"The software tools in Pascal" by Brian Kernighan. On top
of the original version it adds command "t" - copy block
of text to a given line and also commands "y" - yank and
"x" - put. The limitation is that global commands are not
implemented however the behaviour of "s" (substitute) command
is indeed global, so you can say "1,$s/pat/sub/" and have the
pattern "pat" being replaced with "sub" string. Also "!" command is
not available since I simply don't need it