Merge branch 'calvarez/final-webstat-improvements'
- calvarez/final-webstat-improvements: WebStat: fix minor bugs WebStat: added collection statictics WebStat: add custom query summary WebStat: added custom query summary BibRank: add support for flot graphs WebStat: add Apache and Invenio error log analyzer WebStat: add error analyzer WebStat: additional stats and various improvements
- Amendments done during merge: Keep previous CFG_BIBRANK_SHOW_DOWNLOAD_GRAPHS default value. Fix installation of jquery-ui-1.7.3.custom.min.js.