Fix issue #90

Fixes a problem due to Xorg bug
https://bugs.freedesktop.org/show_bug.cgi?id=7430
and similar problems where pressing and releasing a key
generates two different keysym in Xorg.
Updated Website URL
Merge pull request #352 from giox069/next

Fix issue #90 and website URL
Added printer redirection, code cleanup
Fix to printer redirection, added smartcard redirection
GTK3 migration - ftp_client gstock
Fix freerdp connection closing
Update rdp_plugin.c
Merge branch 'next' of github.com:giox069/Remmina into giox069-next
Merge branch 'giox069-next' into next
Rename relevant CB_FORMAT to CF

Update Remmina to be compiled with the latest changes in
FreerRDP 1.2. Many thanks to @tachylatus for the patches.
Merge pull request #364 from giox069/next

Rename relevant CB_FORMAT to CF, many thanks to @tachylatus.
Fix possible crash when closing RDP connection

Fixes a crash detected on remmina 1.2 when closing a connection
window with alt-f4
GTK3 migration - GTK_STOCK deprecated
GTK3 upgrade - gtk_action_is_sensitive has been deprecated since version 3.10
GTK3 upgrade - GTK_STOCK deprecated and gtk_image_set_from_stock #365
GTK3 upgrade - GTK_GRID fixes #365
Switched to GTK+3.6 threading model, make pthreads compulsory.

Many changes to call GTK/GDK functions only on main thread.
Now libphtreads is compulsory.