Update mono ancillary ports

[dbn]

Summary

TODO:

• submit patches upstream (https://github.com/mono/gnome-sharp/pull/3)

NOTE: net/avahi-sharp depends on net/avahi-app, which is maintained by gnome@

Commit message:

Update ancillary mono ports

x11-toolkits/gnome-sharp20:
 - update to version 2.24.4
 - use github for sources
 - use autoreconf and provided bootstrap script (pre-configure)
 - remove gettext-runtime, not used by port
 - order USES section, move non-USES related variables to own section

x11-toolkits/gtk-sharp20:
 - update to version 2.12.45
 - remove gettext-runtime, not used by port
 - order USES section, move non-USES related variables to own section

Test Plan

• Check portscout
• portlint
• Exp-run (http://dbn.westeurope.cloudapp.azure.com/$VER-i386-default-mono-ancillary/latest/build.html) where VER in (10_3; 11_1; 12)

[mat]

Could you use devel/arcanist, or at least generate a diff with full context like it does, with svn diff -x -U9999 or git diff -U9999.

[dbn]

Give full context (apologies, I keep forgetting) and order the USES block.