Improve support for right-to-left languages

[oktaal]

Currently absolutely minimal support is in place in the search highlighter. I couldn't get the test to work with wildcards or quotation marks, because the mixing of those symbols cause confusion. At the very least for the developer. This could definitely be improved, maybe by using native symbols from those writing systems or adding some mode support for switching direction.

[jgonggrijp]

This is slightly more urgent than the CJK issue (though perhaps still not terribly urgent), because I-analyzer is already being used for Hebrew. Perhaps you can use tags to indicate the level or urgence?

[lukavdplas]

May be fixed by #1076 ? @Meesch can you look into this?

[lukavdplas]

@Meesch now that the new highlighter is merged, can you see if this is resolved?

[Meesch]

Addressed by #1207