use libclipboard to access x clipboard if running under terminal with no far2l extensions

[unxed]

https://github.com/jtanx/libclipboard

[elfmz]

• i still dont understand why use terminal version while having x11 env undr the hands, and bringing x clipboard access into terminal version makes it little bit more weird:)
• this lib is x11 only, no wayland
• summaryzing, its better to implement using xclip utility, if will really implement this. May be through glue script, like mounts.sh etc...

[unxed]

We regularly see people running text version on X desktop here in issues. Apparently, the love for the familiar terminal is affecting. xclip is ok of course :)

[demimurych]

• i still dont understand why use terminal version while having x11 env undr the hands, and bringing x clipboard access into terminal version makes it little bit more weird:)

because the terminal version is much faster.
because the terminal is everywhere, even in x ;) even in the browser there is a terminal. even the terminal has a terminal. ;)
because I know how to have 100500 fars in one terminal session, and I don’t know how to do the same in X without creating 100500 windows.
Etc...

By the way, in ubuntu 20.04, ctrl+c in far2lc dont work.

[elfmz]

Regarding 'faster' i'm really not sure. For me WX version has much better reaction time, but may be its subjective impression due to ESC-related issues.
Regarding tab-ed interface - its really missing feature that could be good to have.

[unxed]

dup of #810