[MRM-966] submitted by Jevica Arianne Zurbano - added advanced search in documentation additional changes: - updated the screenshots submitted to reflect the changes in the ui
archiva/trunk/archiva-docs/src/site/apt/userguide/searching.apt
archiva/trunk/archiva-docs/src/site/resources/images/advanced-search.jpg
archiva/trunk/archiva-docs/src/site/resources/images/search-results.jpg
