Fixed issue #1566: Frequent crashes when searching log

Guard access to git_open_log so that it does not infer with the async diff thread.

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Synced translations with Transifex

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Added language pack for Portuguese (Portugal)

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Fixed typo in language script

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Prepared release and bumped version numbers to 1.8.2.0

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Updated libgit2

Signed-off-by: Sup Yut Sum <ch3cooli@gmail.com>