pimcore memcache and mysqltable cache backend bugfixes

git-svn-id: http://www.pimcore.org/svn/pimcore/private/core/trunk@3207 1f8fe7d8-47f0-464c-8d0a-336f4953ab05
document page: generate screenshot optimizations + removed temp. html2canvas because the results are very bad

git-svn-id: http://www.pimcore.org/svn/pimcore/private/core/trunk@3208 1f8fe7d8-47f0-464c-8d0a-336f4953ab05
bugfix for rev. 3207 : pimcore memcache and mysqltable cache backend bugfixes ;-)

git-svn-id: http://www.pimcore.org/svn/pimcore/private/core/trunk@3209 1f8fe7d8-47f0-464c-8d0a-336f4953ab05
build auto version (2786) ...

git-svn-id: http://www.pimcore.org/svn/pimcore/private/core/trunk@3210 1f8fe7d8-47f0-464c-8d0a-336f4953ab05