Was it Allah?

Mohammed?

Or the compilers of Quran?

In sura 59 (ol-Hashar), however, God takes pride in the eradication of the Nadir tribe and describes it as a merited punishment for their persistent adherence to Judaism. Abdollah b. ol-Abbas is reported to have given the name Surat Bani'n-Nadir to this sura.

http://ali-dashti-23-years.tripod.com/

Is that not interesting? I never thought about it, I always assumed the name of the chapter came down with the revelation. Were the revelations even chaptered?

I've found this:

Please note that there are alternate titles for several of the Surahs; the titles are not considered part of the canonical, revealed Qur'an. Notably, Surah 17 is known both as Al-Isra, typically translated The Night Journey and Bani Israel, typically translated The Children of Israel.

http://www.sacred-texts.com/isl/htq/index.htm
The numbering is certainly screwed up. IIRC, apart from the opening sura they're numbered in order of their length. This may well have been done in an attempt to screw up studies of the contradictions / abrogations and to blur the fact that they got considerably more bloodthirsty after Mo and his mates fled Mecca for Medina.