Reformat Manual.rst. Add <date> to change-log. Best practice to extract git commit titles since last version.

New Version v0.17.5.

.*rst: Migration back from qfq-doc to qfq

Release.rst: Request from Myriam Steinbrecher to enlarge placeholder value in FormElement. Old 512, New 2048.

Implemented the option to make a form `readonly`. this can be done statically or dynamically via variable (e.g. SIP).
QuickFormQuery.php, AbstractBuildForm.php: Force 'readonly' by overwriting FormElement individual 'mode' setting.
BuildFormBootstrap.php: Introduced new variable F_SHOW_BUTTON.

#3431 / typeAheadSql: columnname 'key' is a reserverd SQL statement - replace by 'id'. Additional the parametername 'typeAheadLdapKeyPrintf' renamed to 'typeAheadLdapIdPrintf'.
typeAhead.php: fixed typo.
TypeAhead.php: introduced new mapping from 'id' (SQL) to 'key' (API).
AbstractBuildForm.php: Constant renamed.
Database.php: update function makeArrayDict() to reflect name mapping.