Update to version 2.10.1

Changelog:

Fixed error with conflicting libvte/Gtk versions
Fixed ebuild (by Ilya Mochalov).
Suppress "invalid option" for -e.
Fixed missing link to math library (by Thomas Koch)
Miminum required version for Gtk-2 changed to 2.24.
Miminum required version for libvte changed to 0.28.
Rebuild po-files due to source changes.