basics settings and structure mode placing
cache invalidation fix
pyflakes fixes
Adds ``=id`` to PageAdmin.search_fields
Merge pull request #2961 from digi604/fix-2904

basics settings and structure mode placing
fixes #2965
Merge pull request #2966 from digi604/fix-2965

fixes #2965 (empty title in publish)
Merge pull request #2964 from Chive/feature/page-search-by-id

Search by exact id in Page Admin
fixes js button switch
Merge pull request #2967 from digi604/fix-2904

fixes js button switch
fixes partially #2939
Merge pull request #2968 from digi604/fix-2939

fixes partially #2939
adds language tabs on page creation
fixes issue #2925
breadcrump working again
use tabs
only modify params on tree view. fixes #2926 and #2927
show more error infos and refresh after error
Merge pull request #2974 from digi604/fix-2946

adds language tabs on page creation
come out of force language on exception