zabbix-server: add extraConfig option

add types to options
zabbix-server: add new optional build options
Add mirrors for sage
tinc_pre: Update to f57d53c
sxiv: update to 1.3-git and fix runtime behaviour

The fix involves using imlib2 built with giflib instead of a libungif.
Initially I split imlib2 into two but other distros seem to build imlib2
with giflib already and everything still builds with giflib version so I
migrated imlib2 to giflib all together.

Closes #4622
emacs24Packages.auctex: 11.87 -> 11.88
Merge pull request #4801 from robberer/pkgs/zabbix-server

zabbix-server: add extraConfig option
Merge pull request #4817 from joachifm/sage-mirrors

Add mirrors for sage