Issue 2165: Support Set cursor style (DECSCUSR, VT520) escape codes.
By xterm patch #282, DECSCUSR 5/6 (blinking bar/steady bar, they are not VT's features) are supported.
These features are already supported by MinTTY/TeraTerm/RLogin.
I think this change was intended to improve the interoperability between them.
If iTerm support this, it will help terminal application developers.
Change macro name, MAKE_COMMAND to MAKE_CSI_COMMAND
Looks great, thank you!