This patch makes the following assumptions:
1. There is no class outside of this codebase that implements the
ParsoidClient interface. According to CodeSearch this appears to be
correct.
2. It is fine to use the Bcp47Code instead of the internal MediaWiki
language code in the "Accept-Language" HTTP header. As far as I
understand this might even qualify as a bugfix.
Depends-On: If059674597e261039df7f4613a89cb08120c3262
Change-Id: Icd160da2d5555891b9a91a0cb966bd36a55f6fdd
This makes the "direct" client and the VRS based client
implement the same interface, so the caller doesn't have to know
which one it is using.
It looks like ParsoidHelper will not be needed if we use this approach.
Change-Id: Ib1c1d7355951fc0765227dd01a9edfc554fc448d