HU.pm up to date URLs and tables

Fixed BAMOSZ website scraping and download stocks directly from www.BET.hu
Tests pass with minimal modification (I used different error messages)

I have rewritten HU.pm, because it was really old and the websites it used changed significantly.

Mutual fund data is pulled from Association of Hungarian Investment Fund and Asset Management Companies (BAMOSZ), as it was done in the 2008-2009 version of HU.pm, but update to a new website layout. Mutual fund data may be searched by ISIN.

Stock data is now pulled directly from Budapest Stock Exchange (BET) instead of www.magyartokepiac.hu, because apparently Magyar Tokepiac has stopped publishing stock price data. Stock data may be searched by ticker or ISIN.

To be honest, I don't trade stocks and don't understand much about them, so the BET data-scraping may be somewhat inaccurate; I tried matching the Hungarian names of the different listed prices to the English ones, I may have been mistaken sometimes. I originally set out to fix HU.pm because I wanted to see my mutual fund's prices in GnuCash, I only rewrote the stock part because I saw it was also badly out-of-date.

I am also not a real Perl programmer (I am more a Ruby guy...), so my code might not be fully idiomatic, to say the least.

Nevertheless, I hope someone will find this useful!