Increased GERBIL QA version to 0.2.5.

#250, #344 - added option to upload dataset and answer file

fixed #207

Added changes from our online instance.

Merged with v1.2.6 and up to Jena3.1

update sql where language is null not empty string

Merged version1.2.5 into the master branch.

Changed the version to 1.2.3.

Updated the readme.

Following the ISWC reviews, I added a link to the wiki.

Merge branch 'QuestionAnswering' of https://github.com/AKSW/gerbil.git …

…into QuestionAnswering