Implemented for Checkbox.

Index.rst, AbstractBuildForm.php: split buildCheckbox() in constructCheckbox(Simple|Multi)Plain() and constructCheckbox(Simple|Multi)Button.

AbstractBuildForm.php, OnArray.php: new function removeEmptyElementsFromArray(). Replace old check of isset() (which seems never have been worked) against ==''.

Implemented for Radios. Checkbox is still open.

Index.rst, AbstractBuildForm.php, BuildFormBootstrap.php, Constants.php: split buildRadio() in constructRadioPlain() and constructRadioButton. After several tries to make a base function for both construct variants, CR decided that the code is much more easier to read with to complete separate layout functions.

AbstractBuildForm.php: Notes of input elements as well as the text of a 'Note' FormElement are now wrapped in the class 'qfq-note' - this aligns the text to the label baseline.

AbstractBuildForm.php: #2064 / Input Elemente die als JSON response 'value=false' bekommen, zeigen 'false' an -- check if a FormElement is a real tableColumn by using STORE_RECORD is a bad idea, cause new records always deliver 'false'. Now take the STORE_TABLE_COLUMN_TYPES as a reference.

formEditor.sql: Form.name restritcted for checktype from 'all' to 'alnumx' - play formEditor.sql. Check old formnames!

#3253: STORE_TYPO3: steht waehrend Update / Save nicht zur Verfuegung - wird aber benoetigt. Bsp: feUser, beUser, pageId, ...

CODING.md: described implementation.
Store.php: fixed setting of STORE_SYSTEM / showDebugInfo during API call.

#3253: STORE_TYPO3: steht waehrend Update / Save nicht zur Verfuegung - wird aber benoetigt. Bsp: feUser, beUser, pageId, ...

Thought that problem of #2064 is based on #3253 - that was wrong.
#3253 implemented, but not heavily tested.

#2064: problem was that for a non existing tablecolumn, has been searched for a default value - which obviously does not exist. In AbstractBuildForm.php, Line 419, a check implemented if the current FormElement is an existing tablecolumn. If not, do not change the empty value.

FormAction.php, FillStoreForm.php, Store.php, QuickFormQuery.php, Save.php: Refactor setVarArray() to setStore()

#3253
FillStoreForm.php: If there is no STORE_TYPO3, get the old values from SIP: CLIENT_TYPO3VARS.
Store.php: new function fillTypo3StoreFromSip(), copyT3VarstToSip()

Link.php: add some doc.

AbstractException.php: Add catch CodeException to not recursively throw the same exception again and again.
Store.php: constructor of class Store seems to be the best place to do the check.

UserManual/Index.rst: Add doc for htmlAfter, htmlBefore

Form.parameter & FormElement.parameter: Lines starting with '#' are treated as comments and will not be parsed.

Evaluate.php: parseArray() will skip lines starting with a '#'

AbstractBuildForm.php: templateGroup / row with the 'add' button , will be wrapped with the bs*Columns as defined in the FormElement templateGroup.

FillStoreForm.php: fixed problem with checkBoxes in templateGroups. During fillStoreForm the template group has been expanded to all possible elements - the logic for checkboxes expected that at least the '_h_<fe name>' Post Variable exist - which is not true for unexpanded elements.

templateGroup: fixed problem with missing <div class='qfq-line'> around each copy of prefilled templateGroup.
 AbstractBuildForm.php: pattern  '%d' will be replaced by number of copy in FormElement 'label' and 'note'. Recode Logic to wrap templateGroup copies.

AbstractBuildForm.php: implemented function templateGroupCollectFilledElements(). Add function.

AdministratorManual/Index.rst: extend sphinx setup doc, fix typo
UserManual/Index.rst: add doc for templateGroup
FillStore.php: Implement save for templateGroup