Hungarian translation update by mtomi78.

Closes #3966, #3969, #3973, #4000.
Update zlib to 1.2.8 for the mac builds.
Update png to 1.5.15 for the mac builds.
Simplified Chinese translation update by Peng.

Closes #4017.
Fix off-by-one error in setOverrideMods (strlcpy copies n-1 bytes). Fixes ticket:3567.
Update png for mac builds to 1.5.16.
Automatically build the sequences only on tags.

Not betas or release candidates though.
Merge branch 'bugfixes' into 3.1.

* bugfixes:
  Automatically build the sequences only on tags.
  Update png for mac builds to 1.5.16.
  Fix off-by-one error in setOverrideMods (strlcpy copies n-1 bytes). Fixes ticket:3567.
  Simplified Chinese translation update by Peng.
  Update png to 1.5.15 for the mac builds.
  Update zlib to 1.2.8 for the mac builds.
  Hungarian translation update by mtomi78.

Conflicts:
	macosx/configs/mkdmgs.sh