added json import/export tests

the json facilities can now be used for other tests as well

support for dynamic filter place holders #75

tests for struct stuff still missing
no cache handling, yet

handle page moves #72

fixed tests

allow regexps for page assignments. #70

add namespace and suffix config for Page type #67

allow users to not exist. fixes 66

fixed SQL when only multi values are selected. related to #64

sqlite sequences do not need to be micromanaged

allow validation to modify the value before saving

Add test for pure MultiField-Schema - currently failing

correctly handle multi val columns. fixes #64

now group_concat is used

Add tests for a schema consisting only of multis

copy first multi val to single val on save. fixes #43

method for getting all pages known to struct

moved validation to its own class

the validator class is partly test covered through the entry tests but
dedicated tests might be helpful

Enable sorting by mutiple columns

Test parseSort explicitly

Condense testdata and test for exception

Do not hard-code expected exception

small corrections

Add/adjust tests for changed filter handling

See commit 9dbc32ae40e6ae835e9edeee14fdde77ad1c59f3

streamline sort direction handling

we now use a boolean everywhere

flatten array returned for URL parameters

fixed naming