Add parsecursor option for file:line:col syntax

This option is disabled by default, and when enabled causes micro
to parse `:line:col` as a location for the cursor rather than
as part of the filename.

Closes #1650
Closes #1685

internal/config/settings.go

@@ -254,6 +254,7 @@ var DefaultGlobalOnlySettings = map[string]interface{}{
 	"infobar":        true,
 	"keymenu":        false,
 	"mouse":          true,
+	"parsecursor":    false,
 	"paste":          false,
 	"savehistory":    true,
 	"sucmd":          "sudo",