*8783* Fix hooks '<form>::getlocalefieldnames', '<dao>::getLocaleFieldNames', and '<dao>::getAdditionalFieldNames'

Hi Alec,

As agreed on bugzilla (http://pkp.sfu.ca/bugzilla/show_bug.cgi?id=8783), I backported the solution used in the master branch to ojs-stable-2_4 series.

I updated all Form and Dao classes that I found. 


Regards
Giovani