Added option to copy selection to clipboard

Hi Folks,
I have created patch for mate-terminal 1.8.0 which adds ability to additionally copy selected text into clipboard.
As we all known normally selected stuff goes to primary selection buffer, but for some people which works all day with terminal and some other graphical tools (editors, etc.),
selection buffer tends to mix up with clipboard. User have hard times to track in memory what's in clipboard and what's in primary selection buffer.

Thus I have created patch which additionally makes selection to go to the clipboard. Also I have introduced this option in "General" section in "Profile Preferences".
Text for the checkbox in English is "Copy selected text into clipboard".

Please submit the patch to the mainline of mate-terminal. Also if possible add to the 1.8 branch?

The limitation of this patch is that this only makes copy to clipboard on selection. It does not replace middle mouse button to be used as paste from clipboard. Paste operations in mate-terminal is not affected by this patch.

PS,

There is similar functionality recentely (last year) introduced in to KDE 4.x terminal. Also this option makes similar experience as user founds in Windows version of Putty.

Thank you,