Upgrade tinygettext with STK changes

[Adrián Chaves]

The SuperTuxKart team has been improving the tinygettext library on their own repositories.

We should check the differences between the version of tinygettext that we have and the one that they use, and see if we can use theirs or implement some of their changes in ours.

[leper]

​https://github.com/Grumbel/tinygettext/ seems like there is some upstream again.

[leper]

​https://github.com/Grumbel/tinygettext/pull/2 submitted our changes as a pull request to upstream.

​https://github.com/Grumbel/tinygettext/issues/3 has some diffs from SuperTuxKart.

Updating to latest upstream isn't doable currently as that would require us to switch to C++11 first (#2669).

[historic_bruno]

Replying to leper:

Updating to latest upstream isn't doable currently as that would require us to switch to C++11 first (#2669).

Looks like we can do this as of r16160.

[leper]

In 16168:

Update tinygettext to upstream commit ca0f3ff640. Refs #2522.

Keeps our addition of precompiled.h (r14983), win32/dirent, r15179, r15493, and r16140.

[leper]

In 16169:

Add some tinygettext changes from SuperTuxKart. Refs #2522.

Move some data to RO. Pass some parameters as references.
Taken from ​https://github.com/Grumbel/tinygettext/issues/3.

[leper]

Most of the other changes are not that useful for us (fallback support might be, but the way we add .po files might make that a bit more difficult, and there hasn't been any real reason to add it up until now).

[leper]

In 16172:

Remove use of attribute that breaks the Windows build. Refs #2522.

[leper]

Pull request was merged.

Most of the STK changes were also included, so if we update tinygettext wecould close this ticket.

[leper]

In 16462:

Update tinygettext. Fixes #2522.

Updates to upstream changeset f71a8e5e84bffadd61ac93768b332262989844fd, with some additions
that will be submitted upstream (without the addition of precompiled.h and win32 dirent).

[leper]

​https://github.com/tinygettext/tinygettext/pull/4 for the difference we have compared to the above changeset without the precompiled.h addition and without the win32 dirent change.