0.7.1-rc1

• Improvements:
  • Handle cards without mute switch by graying out the switch
  • Replace deprecated GtkTable with GtkGrid
• Translations:
  • Use modern 'gettext' instead of 'intltool'
  • New translations: Serbian
• Build infrastructure:
  • Switch from Autotools to CMake
  • Make the build reproducible
  • Simplify travis build and only build on debian:unstable