ReportTest.php: implemented various exception tests for missing parameter of _paged

Link.php: Check paged / Paged that the parameter r, table and form are given in the right combination.

ReportTest.php: adjusted test to removed 'p:' parameter

Report.php, Constants.php: introduce constants for report column keywords. Remove code to handle unecessary 'p:' tag for delete links.

Link.php, Report.php, AbstractBuildForm.php, BuildFormBootstrap.php, Constants.php: on various points replaced native string against API_DIR and newly API_DELETE_PHP.

Index.rst, Constants.php: reverted parameter '_table' in delete links back to 'table' - Reason: 'form' needs to be 'form' (instead of '_form') due to many used places already.
Sip.php: move SIP_TARGET_URL back to stored inside SIP - it's necessary for 'delete'-links.

FormAction.php: In case of 'AFTER_DELETE', do not try to load primary record - that one is already deleted.
Sip.php: Do not skip SIP_TARGET_URL as parameter for the SIP.

config.qfq.example.ini: Added comment where to save config.qfq.ini.

QuickFormQuery.php, FormAction.php: '#2931 / afterSave Hauptrecord xId nicht direkt verfügbar' - load master record again, after 'action'-elements has been processed.

UsersManual/index.rst: renamed chapter for formelements. Cleanup formelement types. Wrote chapter 'Detailed concept'

Index.rst: Add note to hierachy chars. Fixed uncomplete doc to a) bs*Columns, showButton. Add classPill, classBody. Rewrote form.paramter.class...

FormEditor: 1) design update - new default background color: grey. 2) per form configureable background colors, 3) Optional right align of all form element labels.
BuildFormBootstrap.php: added new class name 'qfq-label' to form labels - needed to assign 'qfq-form-right' class. Changed wrapping of formelements from 'col-md-8' (wrong) to 'col-md-12'.
QuickFormQuery.php: Set default for new F_CLASS_PILL & F_CLASS_BODY.
formEditor.sql: New default background color for formElements is blue.
qfq-bs.css.less: add classes qfq-form-pill, qfq-form-body, form-group (center), qfq-color-*, qfq-form-right

#1255: Remove whole 'Log', 'Utils', 'Db' class - completely useless and not used much. As side effect, #1255, has been solved.
report/Db.php|Log.php|Utils.php: deleted - not necessary anymore
Link.php, Report.php: Remove references to deleted classes. Adjusted one call to db->sql().

formEditor.sql: Added ':S0' to make FormEditor more robust - no error message in case formId can't be resolved, but still wrong behaviour.
Constants.php: Prepend '_' to SIP_MAKE_URLPARAM_UNIQ
Evaluate.php: phpstorm shows that 'getDebug()' is not used anywhere - commented.